Handle log spam

This pull request includes 2 commits from pull request #51 (Emit single pushed commit as just a single email) just to avoid trivial merge conflict.  The only relevant commit for this pull request is the one RFC commit at the end.

Note: THIS PULL REQUEST SHOULDN'T BE MERGED; it breaks the tests and it breaks the current workflow for gitolite and normal git installations.

I'm submitting it this way just as a way to ask for ideas for a better way to handle this.  Basically, for normal git or gitolite, these messages would be sent to the user when they do a push.  For gerrit and stash, they won't.  In gerrit's case, they spam the system error log, which is really annoying as these messages are merely informational in nature and are not actual errors.