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.
Use a variable rather than constructor argument for allow_shutdown.

This is consistent with the other options, and makes it easy to see all
the settings.
Report config errors, rather than assertions in IRCClient.
Fix whitespace.
Remove no-op addFactoryArguments calls.

addFactoryArguments is deprecated now.
s/validate_master_option/validateMasterOption/
Add release not an dependency on txgithub. Update code after review.
Update documentation of repoOwner and repoName usage.