Standartized definitions.
Changes to airlock opening:
-Only people with engineering access can open them by hand.
-Crowbarring them open/close now takes some time (~3 sec)
WIP coat rack
Merge pull request #3748 from comma/dev

Merged dev-freeze into dev
Merge branch 'dev' into coathanger
Merge branch 'master' into coathanger
Coat racks. Can hold either labcoat or detective coat.
Tableflips!

You can now flip non-reinforced straight, 1-tile wide tables.
Complete with ugly codersprites for flipped tables.
Flipped tables now have 20% chance to take damage instead of whatever is behind them.
Merge pull request #3750 from Baystation12/master

Master -> Dev-freeze
Can flip weakened reinforced table now too.
Postmerge mapfix.
New sprite.
Merge remote-tracking branch 'upstream/master' into dev
Merge pull request #3752 from Segrain/dev

Dev map.
Cover system.
Tables now give some cover from bullets and beams.
Standing behind the table gives you 20% chance of table taking the hit instead.
Flipped table gives +20%, but only if bullet comes from the side it faces. Otherwise no cover is provided at all.
Lying on the floor gives +20%.

Table takes half of damage human would, and breaks down after its health goes to zero.
Reinforced talbes have double the health, wooden ones - half.
Merge branch 'dev' of https://github.com/Baystation12/Baystation12 into coathanger
Merge branch 'dev' of https://github.com/Baystation12/Baystation12 into lockdown

Conflicts:
	code/game/machinery/doors/firedoor.dm
Merge pull request #3757 from comma/coathanger

Coat rack
Merge pull request #3756 from comma/tableflip

Tableflips & cover system