GitAssetCommitter::reset_git_stage
Makes sure that there's nothing staged. This is called before starting to add files to staging to make sure that we won't accidentally commit some odd changes not related to what we are doing.
This method does not undo any changes in the working tree! So it's safe to use. Should be, at least. Don't blame me if it isn't. Blame someone else. I'm serious. If this method has a bug, I didn't write the method. Never. It was my cat who ran over the keyboard.
Signature
private function reset_git_stage()