This commit changes which variables are static: the Mac (and
presumably the Linux) debug data tells you what variables are static,
by prefixing their names with double_underscores.
The variable names themselves also hint at this: global variables are
prefixed with 'g', and use upper-camelcase, while static variables
use whatever_you_call_this.
Okay so WindowsWrapper.h now just includes Windows.h if it wants
non-portability. This meant I had to split the custom RECT struct
back to the original RECT and unknown nameless struct (one uses
left/right, while the other uses front/back).
