Code review comment for lp:~henninge/launchpad/on-edge

Improved jml's "on-edge" script to show the last automatic merge on db-stable. Very useful if you can't wait to QA your branch on staging!

Also fixed a bug where the code was passing a string into dotted_revno_to_revision_id instead of a tuple, thus causing it to always throw an exception.

Finally, the script now also dectects when the local copy of a branch is actually older than what's on edge/staging.