This is designed to be run as a "change-commit" trigger. See [Perforce's
documentation][1] on how to set up a trigger for your platform.
[1]: http://www.perforce.com/perforce/r12.1/manuals/cmdref/triggers.html
Closes trac #1034.
(imported from commit d94fa4e50637ade2847a96eab8c5514de3811c24)
Since we're using the module outside of a git repository context we
don't have a git config to reference. Instead, we'll just use the
environment variables we're passed.
(imported from commit 8ae707d5d60eb700052e0ee89e7d36c660e00bb6)