title: Update git commit author date when amending
body: <p>I found myself amending my commits quite often. I don't <code>stash</code> so much because I tend to forget I did so, especially when I want to save what I did before I leave or before a weekend, so I do a "draft" commit. Only thing is, when I amend the commit, it is still set to the original author date. Is there a (simple) way to update it when amending?</p>