Energia include guard
remove overloaded constructor that doesn't quite work
examples - more fixes for AVR progmem
Document contributions included
Don't need to include energia.h - arduino.h does that.
Section separators
adapt port output to Tiva (using GPIO port masking feature)
Temporary definition for Tiva/Stellaris flag
Add names to revision credits
Comment cleanup
SCLKPORT tick/tock needs refining
Rearrange some processor checks -
assuming that other processors libraries will behave more like the AVR