New England power tool massacre [CR]

Updates #3800 and adds a bunch more messy and murderous weapons.

* Lajatangs (which I was going to rename until I found that they're in some Dungeons and Dragons sourcebooks as well), both normal and double-chainsaw; two blades or chainsaws on the ends of a quarterstaff.
* Hedge trimmers. Gasoline powered. A cut above (so to speak) the meat carver.
* Circular saws. Battery powered, hard to hit with due to the small size of the blade.

 The chainsaw lajatang is as unwieldy as you'd expect (I saw 600+ moves per attack with a 0-melee skill 16-Str character, and 250+ with 12-melee skill) but it has the newly-functional WIDE flag on it, so you'll nail everything around you IF you hit (and don't have it immediately pulled from your hands). Just be prepared to take some hits while you recover from the swing; it'll mow through crowds easily but it's not a free ticket by any stretch.

Rough comparison with similar items:

* Meat carver: 30 cutting damage
* **Hedge trimmer**: 40 cutting damage
* **Circular saw**: 50 cutting damage
* Chainsaw: 70 cutting damage
* **Chainsaw lajatang**: 140 cutting damage (because damage is no longer stored in a single signed byte)

Comments are welcome for various item values.