Adds various defenses that can control movement between spaces.
---Medieval Tech---
Gates require the same amount of work to open and close.
Portcullises require more work to raise but significantly less work to close.
---Industrial Tech---
Submersible Walls added can be made out of any material.
Submersible Walls can only be submerge when the utility console is manned.
GitHub (For non-steam version and source): https://github.com/json-commits/RetractableDefenses
Credits to Mlie for fixing bugs!
Plans to add holographic walls for spacer era tech.
