I am having the problem that when viewing the repo state in SourceTree, my branch list is cluttered with the <mybranch>.stgit log entries from stgit (same argument as Issue #32).
Instead of not logging at all, would it be possible to not use a branch for the stgit log, but instead an abstract git ref like
refs/stgitlog/<mybranch>
to track the state of the log?

I did a quick test changing

to
return 'refs/stgitlog/%s.stgit' % branch
and as far as I can tell logging, undo, etc. works, as well as having a clean view in SourceTree.

I acknowledge that this would be a breaking change if just edited, so we might want to make the second part of the ref configurable.

If you could confirm that I am not missing anything and you would welcome such a change, I can give a shot at a pull request.