A first pass at more realistic w_class values

Adjusts w_class so you can't put ridiculous objects in your ears.

List of stuff you can put in your ears (please give feedback):

-regular ear stuff (headsets, earmuffs)
-stamp eraser
-xenoarch core sampler
-rock slivers
-syringes and dna injectors
-pills
-droppers
-pens (including meteor pen) and crayons
-bullet casings
-stamps
-film cartridges
-paper
-coins
-rags
-id cards (and fingerprint cards)
-cigarettes, matches, cigarette packs, match packs, cigarette butts
-implanters
-screwdrivers
-lighters (and by extension the syndie c-4 detonator)
-kitchen utensils
-PDA cartridges
-candles
-camera bugs
-toy ammo (snap pops, cap gun ammo, foam darts)
-queen bees
-soul stone shards