Moves around some ZAS stuff and fixes some things in FEA gas mixtures.

ShareSpace now can take a gas mixture as an argument, alongside the usual list of tiles.
Three new procs on gas mixtures, add() multiply() and divide().  Self explanatory.
Zones with unsimulated tiles that sleep will now reset themselves to the average air.
assume_air will only add air to sleeping zones with unsimulated tiles if it can wake the zone up.

Signed-off-by: Mloc <colmohici@gmail.com>
Fix for sunglasses and night vision goggles
Merge pull request #3809 from DJSnapshot/antag

Fix for sunglasses and Night Vision Goggles
Merge pull request #3808 from Mloc/sleepyzas

Moves around some ZAS stuff and fixes some things in FEA gas mixtures.
Code cleanup.
Merge pull request #3810 from Segrain/master

Smallfix.
Merge remote-tracking branch 'upstream/master' into dev
Added vending machine stocking

* Now with more del() than ever before
* Only works if you have the maintenance panel open
Merge pull request #3825 from Kilakk/dev

Added vending machine stocking
Fixed the absent/removed sprite on experimental welding tools.
Added in two new manuals by Magmaram for atmospherics and EVA.
Added two new manuals by MagmaRam to the default engineering manual bookcase.
Updated sprites for the Captain and Centcomm stamps to look a bit more distinctive and official.
Added in sprites for two new manuals by MagmaRam.
Merge pull request #3823 from Iamgoofball/boozetaketwo

Added the Booze Dispenser, the Soda Dispenser, the Bluespace Beaker, and the Cryostasis Beaker.
Merge pull request #3831 from Nanai/dev

Guide/Manual addition, sprite fix!
Added a supermatter crate and supermatter shard crate, with appropriate CE-only open access for cargo.
Merge pull request #3832 from Nanai/dev

Custom item fixes, Supermatter Crates.
Added "Android" and "Robot" alt titles to cyborgs- They spawn with posibrains. Robot alt title waiting on an alt MMI/brain type from Ravensdale, but functions with posibrain right now.
Merge pull request #3833 from Nanai/dev

Cyborg Alt Titles