Erlang plugin for protoc

[Jason Wagner]

https://github.com/TensorWrench/protoc-gen-erlang
https://github.com/TensorWrench/libprotobuf

I wrote this back when the existing protocol buffers implementation
for Erlang didn't support a lot of features. This plugin generates
Erlang OTP-style code. All run-time dependencies are Erlang-only.

More information is at
http://www.tensorwrench.com/2012/02/protocol-buffers-for-erlang/