* Rename the `squash` alias to `prepare` to repurpose it.
* Change `squash` alias to `git commit --squash=<commit>`.
* Add `fixup` alias to `git commit --fixup=<commit>`.
* Set the `rebase.autoSquash` config option to `true`.
When `git load` is invoked it will check if the subject of the `HEAD`
commit message is `temp!`, if it is when the commit will be reset,
otherwise an error message is output and the commit remains untouched.
