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-freeze
Sprite fix.
Smallfix.
Quickfix.
Balance fix.
Fix for #3804.
Merge pull request #3812 from Segrain/dev-freeze

Dev-freeze bugfixes.
Fixes #3801, C4 will no longer destroy the analyzer it's inside of

Committed to dev-freeze because the fix doesn't work with the click code on master
Small fix so voting isn't always shouting at you for not being an admin or mod.
Merge pull request #3822 from Kilakk/dev-freeze

Fixes #3801, C4 will no longer destroy the analyzer it's inside of
(hopefully) Final fix for ZAS for 0.1.4.

Signed-off-by: Mloc <colmohici@gmail.com>
Merge pull request #3824 from DJSnapshot/dev-freeze

small fix to autotransfer voting
Merge pull request #3827 from Mloc/weirdair

(hopefully) Final fix for ZAS for 0.1.4.
Hopefully.  Hopefully was the key word.

Signed-off-by: Mloc <colmohici@gmail.com>