Added Adafruit GFX library for the display module.
Added Adafruit's sample code for a temperature reading.
Compiles and the target is currently set for the MEGA (for now, until I can replace the Adafruit library with my own and target the Uno/Duemilnova).
Moved code to display setup and handler methods so they can get moved out to their own files eventually.
Moved more logic into their own methods.
Renamed defines so it is clear who is using them.
Moved the const ints to an enum.
Probably will convert to a list of consts so there are no wacky types.