Weather logging & temperature based decay;
+ Stores temperature & wtype of every (occured) weather change to
  save/weather.CharacterName.log
+ (item->rotten) Calculates food decay based on RL double-every-10C
  rule, based on old decay rate at 65 degrees. Stores resulting value
  and last-checked timestamp to itemvars, in anticipation of moving
  to different environments (fridges etc)
+ Various changes to item save/load code to cache the above into pure
  integer variables.

Conflicts:

	game.cpp
weather logging: re-enable versioning
uimenu: latest, which includes 'addentry' as menu is used to dump wlog
baseobject class (testing). This is intended to allow more efficient
lookup of object containers/locations from within the relevant function;
ie, item->rotten should quickly determine it's in a fridge without the need
for iterating through 11*12^2 potential storage vectors

Conflicts:

	item.h
	map.cpp
	vehicle.h
Merge pull request #8 from atomicdryad/esc-weatherlog

weather log