Add docs on developing against Review Board and maintaining forks

Review Request #1014 — Created Sept. 1, 2009 and submitted — Latest diff uploaded

Information

Review Board
master

Reviewers

This is a new batch of docs that detail how to begin working on contributing to Review Board. It explains how to set up a development tree, the basics of branches, and contributing changes back.

There's also some docs in there for maintaining a fork of Review Board using GitHub or a custom solution.
Built the docs and read through them a bit.