Improved Bazaar SCM support

Review Request #668 — Created Dec. 15, 2008 and submitted — Latest diff uploaded

Review Board SVN (deprecated)
Improved BZRTool. The highlights are:

  * It no longer chokes on diffs with new files -- and it properly identifies them as such.
  * It pays attention to basedir. If you point Review Board to a bzr repo, you can use the basedir field to specify the branch to which your diff applies.
Created reviews & viewed their diffs against a bzr repo, including added, modified, and deleted files.