Arduino F() macro.

Testing RAM usage and sketch size:
// #define USE_F_MACRO		vs.	#define USE_F_MACRO

*Not* using F():			Using Arduino F() macro:
Binary sketch size: 7,206 bytes		Binary sketch size: 7,534 bytes
RAM: 465				RAM: 1525

nice :)
Testing RAM and sketchsize influence of Arduino F() macro.