- Drop the mapping for `:Gcd` as I rarely use it and prefer to commit
with one keystroke less.
- Add the current file instead of calling `git add -p` for the whole
repository. If I want to add hunks I can do that with the gitgutter
mappings.
- Add mappings to stash and checkout the current file.
- Use mnemonic 'add' instead of 'stage' for `GitGutterStageHunk`
mappings.
TODO: Extend gitgutter for a `GitGutterStashHunk` function