Full rutime working, Lite generator and runtime building but untested
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs
new file mode 100644
index 0000000..25a62f5
--- /dev/null
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs
@@ -0,0 +1,227 @@
+// Generated by ProtoGen, Version=0.9.0.0, Culture=neutral, PublicKeyToken=8fd7408b07f8d2cd.  DO NOT EDIT!
+
+using pb = global::Google.ProtocolBuffers;
+using pbc = global::Google.ProtocolBuffers.Collections;
+using pbd = global::Google.ProtocolBuffers.Descriptors;
+using scg = global::System.Collections.Generic;
+namespace Google.ProtocolBuffers.TestProtos {
+  
+  public static partial class UnitTestImportLiteProtoFile {
+  
+    #region Extension registration
+    public static void RegisterAllExtensions(pb::ExtensionRegistry registry) {
+    }
+    #endregion
+    #region Static variables
+    #endregion
+    #region Extensions
+    internal static readonly object Descriptor;
+    static UnitTestImportLiteProtoFile() {
+      Descriptor = null;
+    }
+    #endregion
+    
+  }
+  #region Enums
+  public enum ImportEnumLite {
+    IMPORT_LITE_FOO = 7,
+    IMPORT_LITE_BAR = 8,
+    IMPORT_LITE_BAZ = 9,
+  }
+  
+  #endregion
+  
+  #region Messages
+  public sealed partial class ImportMessageLite : pb::GeneratedMessageLite<ImportMessageLite, ImportMessageLite.Builder> {
+    private static readonly ImportMessageLite defaultInstance = new Builder().BuildPartial();
+    public static ImportMessageLite DefaultInstance {
+      get { return defaultInstance; }
+    }
+    
+    public override ImportMessageLite DefaultInstanceForType {
+      get { return defaultInstance; }
+    }
+    
+    protected override ImportMessageLite ThisMessage {
+      get { return this; }
+    }
+    
+    public const int DFieldNumber = 1;
+    private bool hasD;
+    private int d_ = 0;
+    public bool HasD {
+      get { return hasD; }
+    }
+    public int D {
+      get { return d_; }
+    }
+    
+    public override bool IsInitialized {
+      get {
+        return true;
+      }
+    }
+    
+    public override void WriteTo(pb::CodedOutputStream output) {
+      int size = SerializedSize;
+      if (HasD) {
+        output.WriteInt32(1, D);
+      }
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public override int SerializedSize {
+      get {
+        int size = memoizedSerializedSize;
+        if (size != -1) return size;
+        
+        size = 0;
+        if (HasD) {
+          size += pb::CodedOutputStream.ComputeInt32Size(1, D);
+        }
+        memoizedSerializedSize = size;
+        return size;
+      }
+    }
+    
+    public static ImportMessageLite ParseFrom(pb::ByteString data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(pb::ByteString data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(byte[] data) {
+      return ((Builder) CreateBuilder().MergeFrom(data)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(byte[] data, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(data, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(global::System.IO.Stream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
+    }
+    public static ImportMessageLite ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ImportMessageLite ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(pb::CodedInputStream input) {
+      return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
+    }
+    public static ImportMessageLite ParseFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {
+      return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
+    }
+    public static Builder CreateBuilder() { return new Builder(); }
+    public override Builder ToBuilder() { return CreateBuilder(this); }
+    public override Builder CreateBuilderForType() { return new Builder(); }
+    public static Builder CreateBuilder(ImportMessageLite prototype) {
+      return (Builder) new Builder().MergeFrom(prototype);
+    }
+    
+    public sealed partial class Builder : pb::GeneratedBuilderLite<ImportMessageLite, Builder> {
+      protected override Builder ThisBuilder {
+        get { return this; }
+      }
+      public Builder() {}
+      
+      ImportMessageLite result = new ImportMessageLite();
+      
+      protected override ImportMessageLite MessageBeingBuilt {
+        get { return result; }
+      }
+      
+      public override Builder Clear() {
+        result = new ImportMessageLite();
+        return this;
+      }
+      
+      public override Builder Clone() {
+        return new Builder().MergeFrom(result);
+      }
+      
+      public override ImportMessageLite DefaultInstanceForType {
+        get { return global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.DefaultInstance; }
+      }
+      
+      public override ImportMessageLite BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
+        ImportMessageLite returnMe = result;
+        result = null;
+        return returnMe;
+      }
+      
+      public override Builder MergeFrom(pb::IMessageLite other) {
+        if (other is ImportMessageLite) {
+          return MergeFrom((ImportMessageLite) other);
+        } else {
+          base.MergeFrom(other);
+          return this;
+        }
+      }
+      
+      public override Builder MergeFrom(ImportMessageLite other) {
+        if (other == global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.DefaultInstance) return this;
+        if (other.HasD) {
+          D = other.D;
+        }
+        return this;
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input) {
+        return MergeFrom(input, pb::ExtensionRegistry.Empty);
+      }
+      
+      public override Builder MergeFrom(pb::CodedInputStream input, pb::ExtensionRegistry extensionRegistry) {
+        while (true) {
+          uint tag = input.ReadTag();
+          switch (tag) {
+            case 0: {
+              return this;
+            }
+            default: {
+              if (pb::WireFormat.IsEndGroupTag(tag)) {
+                return this;
+              }
+              ParseUnknownField(input, extensionRegistry, tag);
+              break;
+            }
+            case 8: {
+              D = input.ReadInt32();
+              break;
+            }
+          }
+        }
+      }
+      
+      
+      public bool HasD {
+        get { return result.HasD; }
+      }
+      public int D {
+        get { return result.D; }
+        set { SetD(value); }
+      }
+      public Builder SetD(int value) {
+        result.hasD = true;
+        result.d_ = value;
+        return this;
+      }
+      public Builder ClearD() {
+        result.hasD = false;
+        result.d_ = 0;
+        return this;
+      }
+    }
+    static ImportMessageLite() {
+      object.ReferenceEquals(global::Google.ProtocolBuffers.TestProtos.UnitTestImportLiteProtoFile.Descriptor, null);
+    }
+  }
+  
+  #endregion
+  
+}