Journal 2016 01 01

First commit of the year! Added Timer 2 setup for Tick interrupt.

A bit later: Cleaned up text. Added dive structure and defines for new modes.

Next bits:

1. Collect analog data without interfering with edge collection
2. Trigger dive
3. Cancel dive manually
4. Cancel dive on excess dive time
5. Closed-loop control of dive
6. Surface after submerged time at depth

Ensure WD timer is reset and that it is not declared a no-signal condition.