1. Pressurization starts when door closes, and filling automatically starts after pressurization;
2. Depressurization starts automatically after an overfill;
3. Door opens automatically when bottle depressurizes;
4. Door solenoid only opens if door is closed. Solenoid then closes when door switch opens;
5. Platform will not lower with door closed. This prevents defeating the door switch by taping the switch in closed position (say).
Adds version tracking variables
Merge branch 'feature/Safety_Door_/_Refinements' into develop
Minor cosmetic cleanups to code.