Body temperature damage now uses species values

Conflicts:
	code/modules/mob/living/carbon/human/life.dm
Fluff item - mercy robes

Donator fluff sprites
Body temperature fixes and updates

Body temperature regulation is now based on species, and environmental
temperature now respects the air density when affecting living/humans.
This also fixes some bugs with heat/cold protection handling and
improves the way synthetic species body temperatures are handled to be
much more logical.

IPCs always gain temperature but cool down because of their environment.
When the heat transfer to the environment is reduced because of the lack
of air, this will cause IPCs to heat up.

As well, having an infection will increase your body temperature, and
body scanners now detect infections.

Conflicts:
	code/modules/mob/living/carbon/human/life.dm
	code/modules/mob/living/carbon/species.dm
Merge branch 'master' of https://github.com/ZomgPonies/Paradise
Cleans up organ processing

Conflicts:
	code/modules/organs/organ.dm
	code/modules/organs/organ_internal.dm
Infections now spread between organs

Infections can now spread between internal and external organs.
Also changes the organ_failure random event to cause an infection
instead.

Conflicts:
	code/modules/events/organ_failure.dm
	code/modules/organs/organ.dm
Fixes #5311
Fixes #5264
Viruses are properly transferred to spilled blood now.
Antigens prevent from infection properly.
Lowered frequency of blood puddle virus check to cut down on processing.

Conflicts:
	code/game/turfs/simulated.dm
	code/modules/mob/living/carbon/human/life.dm
	code/modules/organs/blood.dm
	code/modules/reagents/Chemistry-Reagents.dm
Compile fix
Cleans up train latching/unlatching

Also adds a verb for turning off train engines.

Conflicts:
	code/modules/vehicles/cargo_train.dm
	code/modules/vehicles/train.dm
Merge pull request #237 from ZomgPonies/master

MY LOVE IS LIKE A TRUCK BERZERKER