Go binding for proton

[aconway <ac...@redhat.com>]

I've pushed the Go binding to master, read all about it at 

https://github.com/apache/qpid-proton/blob/master/proton-c/bindings/go/
README.md

The documentation needs a lot of work but you can check the examples
and start playing with the code now.

Please ignore the packages go/amqp, go/messaging and go/event listed at
the end of the reference doc page. They are old and out of date and I
have not figured out how to get them off the godoc page yet.

Feedback most extremely welcome!

Cheers,
Alan.