Managing your web site with Mercurial

I use the Mercurial source control system for (nearly) every one of my free software projects. Recently, I began using it to manage all of my web sites. If you are like me, you likely have a web server and SQL server of some sort running on your desktop, permitting you to work locally. I make many frequent changes to my sites. Sometimes things don't go so well for various reasons. I may need to