Initial GitHub status receiver.
Switch to txgihub and use interpolation for resolving repo owner and name.
Move documentation into user manual.
Move documentation into user manual.
Update documentation. Move start and end message as initialization arguments.
Add tests.
Only use buildbot standard interpolation. Refactor to fix usage of build.render().
Merge branch 'master' into github_status
Log a message if build defines repoOwner and repoName but no sha.
Add basic tests for txgithub.
Add tests for logs.
Handle queued errors.
Fix log handling.
Add release not an dependency on txgithub. Update code after review.
Update documentation of repoOwner and repoName usage.
console: support for multiple codebases.

Changes / Effects:

1) Only the changes in a build is used to compare with the changeset revision.
The revision id from got_revision is not used.

2) If there are multiple builds with the matching changeset the first one
found is used. So if a slave is lost the build is marked as exception. Then
when the build is restarted that will be used instead.

3) Fixed it from loading all builds when multiple codebases is used.
console: check codebase is in build before checking revisions
console: hide box if codebase of change is not in builder.
Merge branch 'master' into github_status
Fix callbacks for buildStarted and buildFinished.