Emergency shutters down have pressure/temperature difference overlays.

Based on the emergency shutter from Paradise.
Merge pull request #6291 from mwerezak/engine

Dev-Freeze Engine Tweaks + Powernet Fixes
Merge pull request #6303 from PsiOmegaDelta/EmergencyShutters

Emergency shutters now have pressure/temperature difference overlays
Adds inflatables to EVA storage.
Fixes several outstanding bugs with new hydroponics.
Fixes most of #6300
Trying to add to previous.
Merge pull request #6310 from Zuhayr/dev-freeze

Dev freeze fixes.
Fixes APCs switching between autoflag 1 and 0 when cell.charge > 10 but not enough charge for one tick

Old APC bug.
Merge pull request #6308 from PsiOmegaDelta/EVA

Adds inflatables to EVA storage
Adds variable power setting to heaters and freezers
APC cell_type is now an actual power cell type
Sets RD server freezer to low power and map fixes

Removed some engine bits that got copied into space and forgotten about.
Attempts to fix #6226

Kind of a hack. A proper fix would look at how humans produce heat.
Increases max SMES output to 250 kW

Was recently updated to that on dev so it shouldn't hurt on dev-freeze.
Merge remote-tracking branch 'upstream/dev-freeze' into engine