Merge touch and screen libraries in
New Examples!
Add SD.h library support

Can now change whether the library compiles for the normal Arduino SD
library or for the SdFat library directly.

Also made a bunch of stuff static so it could be accessed by the static
init() in the PiWatch class. This is mostly driven by the fact that I
can't seem to pass function callbacks when things aren't static. There's
got to be a better way... Need to fork this and play with it.
Seperate PiWatch init

Don't have to provide a touch event callback and it won't start the
touch routines...