Changes to eeprom layout (add wifi, rtc)

Added more wifi related locations

Added eeprom locations for storage of RTC

Made the system space larger within eeprom
Merge branch 'ArduinoDue' of github.com:collin80/GEVCU into ArduinoDue

Merge changes between development machines
Added a preference handler class

The new PREFHANDLER class abstracts away all the details of how
and where values are stored in EEPROM and transparently
allows everything to be retargetted to last known good location
on demand.
Initial support for RTC, changed affected classes to use new prefhandler

Very early support for RTC chipset inherent in the cortex chip

Switched all affected code to use the new preference handler system.
This makes things much more readable yet powerful.
Turned on pref system for throttle and motor ctrl

While previous commits added the preference system this
commit actually enables the use of it for throttle and
motor controller; where previously things were hard
coded for the Due.