Basic usage of blend_mode

Areas - fire and party alarms look better
Druggy 420 blazeit screen looks better
The whiteness of a flash looks nicer. Mob code makes me hesitant to really change this.
The nearsighted/welding mask dither looks better

If you want screenshots just ask.
Merge pull request #1729 from MrPerson/zone_of_the_blenders

Basic usage of blend_mode
Irrigation Botany Changes

Screwdriver to hook up hoses in between anchored trays. If the transfer
amount is over 30 it sets off the irrigation and the units are equally
shared between all the connected trays.
Fixes/Refining
Indention Fixes
Damn it Gia
Fixes issues with the icons and the update_icon()
Slight Icons fixes/tweaks
cleans up reagent_dispenser.dm

water coolers now dispense paper cups into empty hands.
Fixed the runtime error stopping the whole code
tgstation 1.3.1.dmm (r424) themed away mission
Fixed a bug with drinking glasses that made every reagent turn them into glasses of warm beer due to unintentionally overriding the proc. The solution is removing warm beer and flat cola. Rest in penises.
Adds a rarity value to seeds.  CentComm gives points for rare seeds, and for high-potency samples.
Merge branch 'master' of https://github.com/Giacom/-tg-station into 501

Conflicts:
	code/_onclick/hud/hud.dm
	code/_onclick/hud/human.dm
	code/modules/mob/living/carbon/human/life.dm
	icons/mob/screen_gen.dmi
Merge branch 'master' of https://github.com/tgstation/-tg-station into 501
Fixed the .dme
Refactored the code to remove most icon operations for changing an icon's colour. I had to manually set all the icons, which are subject to colour change, to be have a white/grey icon, so that the colours added properly, and then have them coloured in the code. This means the icons for runes, the reagent beaker overlay, smoke and etc will all be white. They now all use the new 500+ color variable.

The only noticeable gameplay difference is that you can't choose your graffiti's shade.
Changed the base colour sprite for the chempuff.dmi
Fixed a typo.
 * Removed the icon operations from the kitty ears by removing their changing colour gimmick.
 * Removed hacky checks for the item.
Fixes the species property for grown items by removing it (it wasn't being set by slimes or spawn, and was pointless).

Removes some debug lines.
Puts the shuttle timer back to 1200.