Winterized Army Gear for military professions.

Because the loaded gun is the LAST thing they give to new soldiers. If we're
really going to have the game start in a snowstorm, even if it's for 'just a few days', then US Military
service members of all people shouldn't be scrambling for warmer
civilian clothes at the jump.

Adds winter_jacket_army, winter_pants_army, and winter_gloves_army to
armor.json and item_groups.json, as well as the three current military
professions in professions.json. Also gives all three military
professions balaclavas, gives recruits army helmets and helmet liners,
and bio soldiers berets.
Should probably cost more, too.