readd ssd sleep

Signed-off-by: Cael_Aislinn <cael_aislinn@yahoo.com.au>

code/modules/mob/living/carbon/human/life.dm

@@ -1078,7 +1078,8 @@
 			else if(sleeping)
 				handle_dreams()
 				adjustHalLoss(-5)
-				sleeping = max(sleeping-1, 0)
+				if(mind.active || immune_to_ssd)
+					sleeping = max(sleeping-1, 0)
 				blinded = 1
 				stat = UNCONSCIOUS
 				if( prob(10) && health && !hal_crit )

code/modules/mob/living/logout.dm

@@ -2,3 +2,5 @@
 	..()
 	if(!key && mind)	//key and mind have become seperated.
 		mind.active = 0	//This is to stop say, a mind.transfer_to call on a corpse causing a ghost to re-enter its body.
+		if(!immune_to_ssd && sleeping < 2)
+			sleeping = 2

code/modules/mob/mob_defines.dm

@@ -223,3 +223,5 @@
 
 	var/has_limbs = 1 //Whether this mob have any limbs he can move with
 	var/can_stand = 1 //Whether this mob have ability to stand
+
+	var/immune_to_ssd = 0