Re-write of EEPROM functions

[nseidle]

This uses the more common EEPROM methods currently built into Arduino. The approach is a lot more complex but handles any size variable and struct more gracefully than previous approach.

I originally hit this problem when trying to record a struct. This new approach works flawlessly.

Tested against examples and various attempts to break it.

[nseidle]

I've got some additional features I need to add. Hold for a bit...

Recording takes too long for multi-byte items (like phone #s). I'll see if I can write a write buffer function.