First cut at new layout
diff --git a/src/ProtocolBuffers/DynamicMessage.cs b/src/ProtocolBuffers/DynamicMessage.cs
new file mode 100644
index 0000000..c05a274
--- /dev/null
+++ b/src/ProtocolBuffers/DynamicMessage.cs
@@ -0,0 +1,414 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.
+// http://code.google.com/p/protobuf/
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+using System;
+using System.Collections.Generic;
+using System.IO;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// An implementation of IMessage that can represent arbitrary types, given a MessageaDescriptor.
+  /// </summary>
+  public sealed class DynamicMessage : AbstractMessage<DynamicMessage, DynamicMessage.Builder> {
+
+    private readonly MessageDescriptor type;
+    private readonly FieldSet fields;
+    private readonly UnknownFieldSet unknownFields;
+    private int memoizedSize = -1;
+
+    /// <summary>
+    /// Creates a DynamicMessage with the given FieldSet.
+    /// </summary>
+    /// <param name="type"></param>
+    /// <param name="fields"></param>
+    /// <param name="unknownFields"></param>
+    private DynamicMessage(MessageDescriptor type, FieldSet fields, UnknownFieldSet unknownFields) {
+      this.type = type;
+      this.fields = fields;
+      this.unknownFields = unknownFields;
+    }
+
+    /// <summary>
+    /// Returns a DynamicMessage representing the default instance of the given type.
+    /// </summary>
+    /// <param name="type"></param>
+    /// <returns></returns>
+    public static DynamicMessage GetDefaultInstance(MessageDescriptor type) {
+      return new DynamicMessage(type, FieldSet.DefaultInstance, UnknownFieldSet.DefaultInstance);
+    }
+
+    /// <summary>
+    /// Parses a message of the given type from the given stream.
+    /// </summary>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, CodedInputStream input) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(input);
+      return dynamicBuilder.BuildParsed();
+
+    }
+
+    /// <summary>
+    /// Parse a message of the given type from the given stream and extension registry.
+    /// </summary>
+    /// <param name="type"></param>
+    /// <param name="input"></param>
+    /// <param name="extensionRegistry"></param>
+    /// <returns></returns>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, CodedInputStream input, ExtensionRegistry extensionRegistry) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(input, extensionRegistry);
+      return dynamicBuilder.BuildParsed();
+    }
+
+    /// <summary>
+    /// Parses a message of the given type from the given stream.
+    /// </summary>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, Stream input) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(input);
+      return dynamicBuilder.BuildParsed();
+    }
+
+    /// <summary>
+    /// Parse a message of the given type from the given stream and extension registry.
+    /// </summary>
+    /// <param name="type"></param>
+    /// <param name="input"></param>
+    /// <param name="extensionRegistry"></param>
+    /// <returns></returns>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, Stream input, ExtensionRegistry extensionRegistry) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(input, extensionRegistry);
+      return dynamicBuilder.BuildParsed();
+    }
+
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of the given type and return it.
+    /// </summary>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, ByteString data) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(data);
+      return dynamicBuilder.BuildParsed();
+    }
+
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of the given type and return it.
+    /// </summary>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, ByteString data, ExtensionRegistry extensionRegistry) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(data, extensionRegistry);
+      return dynamicBuilder.BuildParsed();
+
+    }
+
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of the given type and return it.
+    /// </summary>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, byte[] data) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(data);
+      return dynamicBuilder.BuildParsed();
+    }
+
+    /// <summary>
+    /// Parse <paramref name="data"/> as a message of the given type and return it.
+    /// </summary>
+    public static DynamicMessage ParseFrom(MessageDescriptor type, byte[] data, ExtensionRegistry extensionRegistry) {
+      Builder builder = CreateBuilder(type);
+      Builder dynamicBuilder = builder.MergeFrom(data, extensionRegistry);
+      return dynamicBuilder.BuildParsed();
+    }
+
+    /// <summary>
+    /// Constructs a builder for the given type.
+    /// </summary>
+    public static Builder CreateBuilder(MessageDescriptor type) {
+      return new Builder(type);
+    }
+
+    /// <summary>
+    /// Constructs a builder for a message of the same type as <paramref name="prototype"/>,
+    /// and initializes it with the same contents.
+    /// </summary>
+    /// <param name="prototype"></param>
+    /// <returns></returns>
+    public static Builder CreateBuilder(IMessage prototype) {
+      return new Builder(prototype.DescriptorForType).MergeFrom(prototype);
+    }
+
+    // -----------------------------------------------------------------
+    // Implementation of IMessage interface.
+
+    public override MessageDescriptor DescriptorForType {
+      get { return type; }
+    }
+
+    public override DynamicMessage DefaultInstanceForType {
+      get { return GetDefaultInstance(type); }
+    }
+
+    public override IDictionary<FieldDescriptor, object> AllFields {
+      get { return fields.AllFields; }
+    }
+
+    public override bool HasField(FieldDescriptor field) {
+      VerifyContainingType(field);
+      return fields.HasField(field);
+    }
+
+    public override object this[FieldDescriptor field] {
+      get {
+        VerifyContainingType(field);
+        object result = fields[field];
+        if (result == null) {
+          result = GetDefaultInstance(field.MessageType);
+        }
+        return result;
+      }
+    }
+
+    public override int GetRepeatedFieldCount(FieldDescriptor field) {
+      VerifyContainingType(field);
+      return fields.GetRepeatedFieldCount(field);
+    }
+
+    public override object this[FieldDescriptor field, int index] {
+      get {
+        VerifyContainingType(field);
+        return fields[field, index];
+      }
+    }
+
+    public override UnknownFieldSet UnknownFields {
+      get { return unknownFields; }
+    }
+
+    public bool Initialized {
+      get { return fields.IsInitializedWithRespectTo(type); }
+    }
+
+    public override void WriteTo(CodedOutputStream output) {
+      fields.WriteTo(output);
+      if (type.Options.MessageSetWireFormat) {
+        unknownFields.WriteAsMessageSetTo(output);
+      } else {
+        unknownFields.WriteTo(output);
+      }
+    }
+
+    public override int SerializedSize {
+      get {
+        int size = memoizedSize;
+        if (size != -1) return size;
+
+        size = fields.SerializedSize;
+        if (type.Options.MessageSetWireFormat) {
+          size += unknownFields.SerializedSizeAsMessageSet;
+        } else {
+          size += unknownFields.SerializedSize;
+        }
+
+        memoizedSize = size;
+        return size;
+      }
+    }
+
+    public override Builder CreateBuilderForType() {
+      return new Builder(type);
+    }
+
+    /// <summary>
+    /// Verifies that the field is a field of this message.
+    /// </summary>
+    private void VerifyContainingType(FieldDescriptor field) {
+      if (field.ContainingType != type) {
+        throw new ArgumentException("FieldDescriptor does not match message type.");
+      }
+    }
+
+    /// <summary>
+    /// Builder for dynamic messages. Instances are created with DynamicMessage.CreateBuilder.
+    /// </summary>
+    public sealed class Builder : AbstractBuilder<DynamicMessage, Builder> {
+      private readonly MessageDescriptor type;
+      private FieldSet fields;
+      private UnknownFieldSet unknownFields;
+
+      internal Builder(MessageDescriptor type) {
+        this.type = type;
+        this.fields = FieldSet.CreateInstance();
+        this.unknownFields = UnknownFieldSet.DefaultInstance;
+      }
+
+      protected override Builder ThisBuilder {
+        get { return this; }
+      }
+
+      public override Builder Clear() {
+        fields.Clear();
+        return this;
+      }
+
+      public override Builder MergeFrom(IMessage other) {
+        if (other.DescriptorForType != type) {
+          throw new ArgumentException("MergeFrom(IMessage) can only merge messages of the same type.");
+        }
+        fields.MergeFrom(other);
+        return this;
+      }
+
+      public override Builder MergeFrom(DynamicMessage other) {
+        if (other.DescriptorForType != type) {
+          throw new ArgumentException("MergeFrom(IMessage) can only merge messages of the same type.");
+        }
+        fields.MergeFrom(other);
+        return this;
+      }
+
+      public override DynamicMessage Build() {
+   	    if (!IsInitialized) {
+          throw new UninitializedMessageException(new DynamicMessage(type, fields, unknownFields));
+        }
+        return BuildPartial();
+      }
+
+      /// <summary>
+      /// Helper for DynamicMessage.ParseFrom() methods to call. Throws
+      /// InvalidProtocolBufferException 
+      /// </summary>
+      /// <returns></returns>
+      internal DynamicMessage BuildParsed() {
+        if (!IsInitialized) {
+          throw new UninitializedMessageException(new DynamicMessage(type, fields, unknownFields)).AsInvalidProtocolBufferException();
+        }
+        return BuildPartial();
+      }
+
+      public override DynamicMessage BuildPartial() {
+        fields.MakeImmutable();
+        DynamicMessage result = new DynamicMessage(type, fields, unknownFields);
+        fields = null;
+        unknownFields = null;
+        return result;
+      }
+
+      public override Builder Clone() {
+        Builder result = new Builder(type);
+        result.fields.MergeFrom(fields);
+        return result;
+      }
+
+      public override bool IsInitialized {
+      	get { return fields.IsInitializedWithRespectTo(type); }
+      }
+
+      public override Builder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry) {
+        UnknownFieldSet.Builder unknownFieldsBuilder = UnknownFieldSet.CreateBuilder(unknownFields);
+        unknownFieldsBuilder.MergeFrom(input, extensionRegistry, this);
+        unknownFields = unknownFieldsBuilder.Build();
+        return this;
+      }
+
+      public override MessageDescriptor DescriptorForType {
+        get { return type; }
+      }
+
+      public override DynamicMessage DefaultInstanceForType {
+        get { return GetDefaultInstance(type); }
+      }
+
+      public override IDictionary<FieldDescriptor, object> AllFields {
+        get { return fields.AllFields; }
+      }
+
+      public override IBuilder CreateBuilderForField(FieldDescriptor field) {
+        VerifyContainingType(field);
+        if (field.MappedType != MappedType.Message) {
+          throw new ArgumentException("CreateBuilderForField is only valid for fields with message type.");
+        }
+        return new Builder(field.MessageType);     
+      }
+
+      public override bool HasField(FieldDescriptor field) {
+        VerifyContainingType(field);
+        return fields.HasField(field);
+      }
+
+      public override object this[FieldDescriptor field, int index] {
+        get {
+          VerifyContainingType(field);
+          return fields[field, index];
+        }
+        set {
+          VerifyContainingType(field);
+          fields[field, index] = value;
+        }
+      }
+
+      public override object this[FieldDescriptor field] {
+        get {
+          VerifyContainingType(field);
+          object result = fields[field];
+          if (result == null) {
+            result = GetDefaultInstance(field.MessageType);
+          }
+          return result;
+        }
+        set {
+          VerifyContainingType(field);
+          fields[field] = value;
+        }
+      }
+
+      public override Builder ClearField(FieldDescriptor field) {
+        VerifyContainingType(field);
+        fields.ClearField(field);
+        return this;
+      }
+
+      public override int GetRepeatedFieldCount(FieldDescriptor field) {
+        VerifyContainingType(field);
+        return fields.GetRepeatedFieldCount(field);
+      }
+
+      public override Builder AddRepeatedField(FieldDescriptor field, object value) {
+        VerifyContainingType(field);
+        fields.AddRepeatedField(field, value);
+        return this;
+      }
+
+      public override UnknownFieldSet UnknownFields {
+        get {
+          return unknownFields;
+        }
+        set {
+          unknownFields = value;
+        }
+      }
+
+      /// <summary>
+      /// Verifies that the field is a field of this message.
+      /// </summary>
+      /// <param name="field"></param>
+      private void VerifyContainingType(FieldDescriptor field) {
+        if (field.ContainingType != type) {
+          throw new ArgumentException("FieldDescriptor does not match message type.");
+        }
+      }
+    }
+  }
+}