Fully converted over to ICodedOutputStream for all WriteTo derivations
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
index 0cfb0ad..53a076e 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
@@ -450,7 +450,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       if (HasField1) {

         output.WriteString(1, "field1", Field1);

@@ -662,7 +662,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -842,7 +842,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -1037,7 +1037,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -1217,7 +1217,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -1397,7 +1397,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -1577,7 +1577,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -1757,7 +1757,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -1937,7 +1937,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -2117,7 +2117,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }

@@ -2328,7 +2328,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       pb::ExtendableMessage<ComplexOptionType1, ComplexOptionType1.Builder>.ExtensionWriter extensionWriter = CreateExtensionWriter(this);

       if (HasFoo) {

@@ -2647,7 +2647,7 @@
           }

         }

         

-        public override void WriteTo(pb::CodedOutputStream output) {

+        public override void WriteTo(pb::ICodedOutputStream output) {

           int size = SerializedSize;

           if (HasWaldo) {

             output.WriteInt32(1, "waldo", Waldo);

@@ -2870,7 +2870,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       pb::ExtendableMessage<ComplexOptionType2, ComplexOptionType2.Builder>.ExtensionWriter extensionWriter = CreateExtensionWriter(this);

       if (HasBar) {

@@ -3233,7 +3233,7 @@
           }

         }

         

-        public override void WriteTo(pb::CodedOutputStream output) {

+        public override void WriteTo(pb::ICodedOutputStream output) {

           int size = SerializedSize;

           if (HasPlugh) {

             output.WriteInt32(3, "plugh", Plugh);

@@ -3442,7 +3442,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       if (HasQux) {

         output.WriteInt32(1, "qux", Qux);

@@ -3717,7 +3717,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       if (HasXyzzy) {

         output.WriteInt32(7593951, "xyzzy", Xyzzy);

@@ -3928,7 +3928,7 @@
       }

     }

     

-    public override void WriteTo(pb::CodedOutputStream output) {

+    public override void WriteTo(pb::ICodedOutputStream output) {

       int size = SerializedSize;

       UnknownFields.WriteTo(output);

     }