Lots of stuff, see description

Moved weather code into a header
Created rainfall and sunshine functions
Added a function (resourcedrop) to VectorIntLib.h for weather
interaction with soil.
Wrote test code for weather
Integrated weather with resources
Made DimensionStruct use only signed long ints
Organized weather code (put everything in folders)
Rainfall now interacts with non-water resources
Probably other stuff too.

I need to update the resource readme, and write one for weather.
The specific values used for weather (intensity values, halflife, etc)
need to be adjusted. I'm also thinking that the atmosphere starts with
too much water. Not sure what the deal is with CO2, so we'll need to
figure that out.