Added two-way smart cycling airlocks

Features:
- Functionally similar to existing cycle airlocks. 
- Instead of going 1 atm -> 0 atm, the pressure is equalized to the internal/external environmental pressure (both ways). 

Notes: 
- They appear to cycle pretty slow, likely due to the pressure in the pipe net I was using for testing. 
- While testing, I discovered what appears to be a significant bug with zone connections on the current BEF branch (probably has nothing to do with Skymarshal's recent changes) #2627

Possible feature expansions: 
- Add warning and confirm dialogs for specific commands. 
- Add a 'swipe ID' option to override/change some settings. 
- Something to artificially force pumping to be faster.