Possibly it is better to use a version control system, so you get snapshots of the whole development rather than lots of individual files that may also end up being accidentally deployed to a live site?
PhpED itself directly supports a version control system called CVS but I prefer to use Git and I get along just fine without that being integrated into PhpED, although I believe you can integrate it yourself by adjusting the file menus.
Have a look SmartGit
http://www.syntevo.com/smartgit/
Using these sorts of tools, not only do you get historic copies of your site, you also get the ability to compare between versions to see what's changed, do fix-ups, etc.