Pod door tweaks

- Added directional pod door sprites
- Made pod doors change draw layer when they open and close
   - Pod doors draw behind the glass layer when open
   - Pod doors draw in front of the glass layer when closed
Updated Supermatter user manual sprite
Rework of colour mixing
Merge pull request #4313 from RKF45/small

Small
Fixed rad collector toxin drain bug

Removed bad code modifying variables directly and replaced it with a proc that correctly modifies the gas volume.
SMES fix, AI's can now use them.

Thinking this was a typo, though quite honestly I'm not sure why this test
is even here as distance checks are built into nanoUI but since feradan put it in
I'm kinda not wanting to remove it.
Merge pull request #4320 from Loganbacca/bayfix-4315

Rad collector fix
Merge pull request #4317 from Ccomp5950/dev-freeze

SMES fix, AI's can now use them.
Merge pull request #4318 from Loganbacca/engineroom

Engine Room Redesign
Merge pull request #4319 from RKF45/colour

Realistic colour mixing
Merge pull request #4309 from LBraindead/dev

AMEN
Typo fix

Fixes a reagent recipe.
Merge pull request #4321 from Furlucis/master

Typo fix
Admin requested addition of a global dsay toggle.
fix for muting deadme as well.
Engine room redesign fix

Forgot to take the plasma tanks out of the EVA tank dispenser - seeing as there is now a dispenser with only plasma tanks in hard storage.
Merge pull request #4323 from DJSnapshot/hotfix

Admin requested addition of a global dsay toggle
Merge pull request #4316 from RKF45/robots

Fixes for emagging robots
Merge pull request #4326 from Loganbacca/enginefix

Engine room fix
Merge branch 'dev-freeze' of https://github.com/Baystation12/Baystation12 into gun_fixes