Pressure and Humidity now a factor in body temperature [CR] [WIP]

With the new weather system, pressure and humidity can now be a factor in body temperature.

The formula used is : http://en.wikipedia.org/wiki/Wind_chill#Australian_Apparent_Temperature

Wind power is a simple formula, but seems to work. 

Clothing resist wind based on coverage and material. Wool is bad, Cotton isn't good, leather / plastic / bone / chitin / nomex is great, the rest (metal, wood, etc) is almost perfect.

Being inside or underground stops wind and affects humidity. 

The UI is rudimentary. Wind speed is added in mph and a number for relative humidity, is the same color as temperature. However, the @ menu and the + menu now show body temperature on a scale of 0 to 100 instead of warmth. 

Things missing : frostbite isn't affected by windchill as it should. Wind has no direction: a wind map is needed for that and beyond my abilities at the moment. Improved UI probably. Suggestions welcome.
Cache these get_weather calls, like you did the others. =P