1. Minor cleanup of user messages in null loop
2. Cleanup of TO DO items in code
1. Cleaning loop code. WRITTEN ON PLANE; UNVERIFIED. Requires a small hardware change that breaks compatibility
1. Null Loop changes: Now looks for falling pressure as sign that bottle is degassing, not just an arbitrary null pressure
1. Finished and tested Cleaning Mode feature. Changed front panel switch from J11 to J10, and put a jumper across J11.
2. Changed Null Pressure routine to continue depressurization while P1 less than Null Pressure -OR- P1 continues to drop by a certain increment every 1000 ms. Changed time variables from INT to UNSIGNED LONG
Merge branch 'feature/Cleaning_loop' into develop