Added system for viruses to affect only certain species.
Currently it ignores synthetic species competely.
Merge branch 'dev' into virus-racism

Conflicts:
	code/modules/virus2/helpers.dm
Fixes single pane windows not blocking airborne viruses completely.
Stopped braindamage effect from dealing 4 digit amounts of damage to brain organ.
Spaceacilline stronk.
Now it prevents new infections completely, and has a chance to cure virus on early stages (without giving antibodies though.)
Buffed protections.
Full biosuits and spacesuits now protect more against airborne infections, and completely against touch-based ones (when worn with gloves).
More random for random god.
Effects now start with random chance of firing and multiplier (like forced minormutate() on spawn).
Fixed some runtimes with specieism, and blood transfer ignoring viruses' racial preferences.
Made it possible for virus to mutate and affect different species.
Fixed blood injections not transmitting viruses properly.
Keep forgetting that list is associative.
Changed sneezing to spread viruses like cough, but only in front of the mob.
It gives a warning sometimes, so guy has 7 ticks to face elsewhere.
Lowered chance of exhale spreading viruses, as it was firing way too often.
Merge branch 'dev' of https://github.com/Baystation12/Baystation12 into virus-racism

Conflicts:
	code/modules/virus2/helpers.dm
Merge branch 'dev' into virus-racism
Fucking hate this file.
Dreaded changelog.html
Splicing virus changes it's unique ID.
Merge pull request #4567 from comma/virus-racism

Virology shenanigans