Rough draft of the Committing guidelines

This is the rough draft and will have many more changes as we flesh out exactly what we want our committing standards to be.
Note: the Robottelo Standards link will be broken until we create that document.
I'm still looking for the `.. _Robottelo Standards::` directive at the bottom of this file. Try running `rst2html` on this file and opening the output in a web browser.