Added MemoryFree library, fixed two tricky bugs

 - Seems bad to call begin on CurieLCD twice so now we check and if
   it has already been called we do not do anything

 - Something really sketching going on with the F() strings, and
   getting rid of the redefinition of PROGMEM seemed to fix it,
   but now the warnings are back. We will just deal with the warnings.

CurieWifi is much more robust now!