z-order armor by location, now that it has a location.
Update lang/extract_json_strings.py.
Update the .pot file.
Added ear plugs and noise cancelling headgear
Tidy up earplug code
Protectors

Some of the scientists and soldiers apparently drank the water...
Correct json mismatches turned up by new cross-checks.
Tightened the spawning code

Kevin's suggestion worked fine and let me add guards to the drug deal
too.  (The 1/20 for Smokers is intentional.  I hate those things but
they seemed a good check, since drug spawns can drop *nice gear*.)

Tests look good so far.
Merge remote branch 'dda/master' into dda-master
Merge armor drawing tweak, new .pot, and hearing protection.
Merge soldier and scientist zombie spawns.
Format monster spawns in special map locations.