Add git-commit-mode to exempt modes

With current Magit, commit buffers are opened via Emacsclient into [git-commit-mode](https://github.com/magit/git-modes) instead of `magit-log-edit-mode`. Working on the assumption that `magit-log-edit-mode` is already on this list, I've updated it to work the same for current Magit.
Bump version for marmalade
Bumping
Apply just-one-space patch (refs #34)
Add autoload cookie to hook function (refs #35)
Update README code with fences and add example for modeline
Refactor god-mode key interpreter, and add sticky literal keys.
Add handling for return key.