Water_act: Wetlevel for carbon mobs

All carbon mobs have a new variable called wetness, which is increased
upon water_act's that have a volume over 10, and is decreased every 22~
cycles of mob_master.

This variable currently does absolutely nothing but change their examine
text.

code/game/objects/structures/watercloset.dm

@@ -308,6 +308,7 @@
 		check_heat(C)
 
 /obj/machinery/shower/proc/check_heat(mob/M as mob)
+	M.water_act(100, convertHeat(), src) //convenience
 	if(!on || watertemp == "normal") return
 	if(iscarbon(M))
 		var/mob/living/carbon/C = M