Anpassung an 4TE Dev-Board Hardware
Code cleanup

+ Fixed library test code that somehow made it into the repository
+ Changed short to int arguments
+ Removed dead code from bus.cpp
+ Adapted README to new pins
SPI and LCD display

+ added SPI access class (somewhat finished)
+ added graphical LCD access class (unfinished)
SPI and EA-Dogs updates
Match LED pins to 4TE Dev. Board 1.0 layout for examples
Merge selfbus code