Added C# options
Added C# options

Livefyre/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,pldg/protobuf-csharp-port,jskeet/protobuf-csharp-port,phofman/protobuf-csharp-port,pldg/protobuf-csharp-port,angshuman-agarwal/protobuf-csharp-port,google/protobuf,Livefyre/protobuf,angshuman-agarwal/protobuf-csharp-port,Livefyre/protobuf,Livefyre/protobuf,angshuman-agarwal/protobuf-csharp-port,google/protobuf,phofman/protobuf-csharp-port,google/protobuf,Livefyre/protobuf,google/protobuf,google/protobuf,google/protobuf,phofman/protobuf-csharp-port,jskeet/protobuf-csharp-port,pldg/protobuf-csharp-port,jskeet/protobuf-csharp-port,jskeet/protobuf-csharp-port,angshuman-agarwal/protobuf-csharp-port,phofman/protobuf-csharp-port,pldg/protobuf-csharp-port