* Add Bazel support for Go library

* Make flatc compile again.

Was missing java_generator, which is now referenced from source.

* Added '--oneof-union' option.

Used with the .proto -> .fbs converter, will translate protobuff oneofs to flatbuffer unions.
Updated proto test to check both methods of converting oneofs.

* Added '--oneof-union' option.

Used with the .proto -> .fbs converter, will translate protobuff oneofs to flatbuffer unions.
Updated proto test to check both methods of converting oneofs.

* FlatBuffers: Moved MakeCamel() into idl_parser.cpp

Removes library dependency on Java/C# generator code.

For #4574.

To test:

    bazel test --verbose_failures //:flatbuffers_test