check-commit: allow underscore as commit topic It's currently not possible to commit with a changeset topic like 'bash_completion'. This change fixes that.

merge: use labels in subrepo merge This is the last place that doesn't respect conflict labels in merge output. Teach subrepos to use subrepo merge output too.

registrar: make format strings unicodes and not bytes Fixes issues on Python 3, wherein docstrings are unicodes. Shouldn't break anything on Python 2.