refactoring of SystemIO, Status and Webpage
fix glitches in website, enable pre-charge logic
Merge remote-tracking branch 'upstream/ArduinoDue' into ArduinoDue

Conflicts:
	GEVCU.ino
replace HV+/HV- concept with previous
renamed COOLRELAY to COOLFAN
SerialUSB is the default.. small oversight
fixes in the annunciator, some did not work
Merge pull request #62 from neuweiler/ArduinoDue

Status and SystemIO class, refactoring and fixes