Rewrites food slicing, energy weapons

Rewrote food slicing so that any item with the edge var set can slice food. This meant making sure various items have the edge var set correctly, which led to fixing various issues with certain weapons... Mainly energy swords remaining sharp and edgy even when turned off and plastic knives having the same force as regular knives. While I was added I did a bunch of cleanup for energy swords (refactored de/activating to get rid of duplicate code), so this is targeting dev now.
It's really not getting in the way, nor is it even taking up that many lines of code. For this reason I decided to be conservative and leave it. If a PR was opened to get rid of it, though, I'm sure no one will complain.