- I made human/handle_blood() less shitty.

- We no longer leave a blood trail if blood_volume is below a certain level which depends on the brute damage received. This way dragging a wounded player does have a bad effect.
- We no longer give humans a second reagents var containing blood, and we don't put exotic blood in the mob's reagents. Now we don't store any blood substance inside the mob, we only have a blood_volume var. When we draw blood with syringe we create the reagent that match the type (blood reagent, or an exotic blood reagent)
- can't draw blood from mob if it's low on blood, so we can't empty a mob of its blood entirely.
- Removed the blood type preference appearing in character setting.
- blood pack automatically show blood type, unless manually labeled.
- removed bloody_hands_mob human var and same name glove var.
- Some animals now have blood (pets, goat, cows)
- hitting and dragging mobs with actual blood in their veins leaves blood on you and a trail on the floor.
- probably other stuff that I'll mention in the PR.

code/modules/paperwork/contract.dm

@@ -145,9 +145,7 @@
 	add_fingerprint(user)
 	if(M == user && target == M.mind && M.mind.soulOwner == M.mind && attempt_signature(user))
 		user.visible_message("<span class='danger'>[user] slices their wrist with [src], and scrawls their name in blood.</span>", "<span class='danger'>You slice your wrist open and scrawl your name in blood.</span>")
-		if(istype(user, /mob/living/carbon/human))
-			var/mob/living/carbon/human/H = user
-			H.vessel.remove_reagent("blood",10)
+		user.blood_volume = max(user.blood_volume - 10, 0)
 	else
 		return ..()