Give Your Development Domain a Different Favicon Than Production

I got frustrated of not being able to tell the tabs apart as I was working on stuff. So this is my so-dumb-it's-smart solution.

The only hitch in my gittyup was that I had to add it to .gitignore, which untracked the file, which deletes it, and had to manually slip it back onto the server. Although it looks like there are smarter ways.