Support new oneof feature

[GoogleCodeExporter]

Currently, trying to compile a .proto file using new "oneof" feature with 
protogen will make protoc display the following errors:

meta_data2.proto:8:5: Expected "required", "optional", or "repeated".
meta_data2.proto:8:19: Expected field number.

This is of course because the protoc version used by protobuf-csharp-port is 
old and the feature is new. Since oneof is a very desirable feature, it would 
be nice if protobuf-csharp-port would support it.

Original issue reported on code.google.com by [email protected] on 14 Nov 2014 at 3:58

[GoogleCodeExporter]

Yes, agreed - there's a bunch of work I want to do to bring the project up to 
speed with the original project, but I don't have time right now. It's not just 
a matter of updating protoc... there's the code to support it in C# that needs 
writing too :)

I don't have a time frame for this right now, but it *is* on my list...

Original comment by [email protected] on 14 Nov 2014 at 4:01

[GoogleCodeExporter]

Most appreciated Jon

Original comment by [email protected] on 25 Nov 2014 at 7:22

[GoogleCodeExporter]

Any news on getting 2.6 support?

Original comment by [email protected] on 6 Feb 2015 at 9:09

[GoogleCodeExporter]

There are plans to go straight to 3.0. I'm not in a position to give details 
about anything right now, but I definitely intend it to happen. Sorry I can't 
be any more specific.

Original comment by jonathan.skeet on 6 Feb 2015 at 10:24