Merge pull request #7655 from VOREStation/aro-doingafter

Make some progress bar activities exclusive

code/modules/mob/mob_defines.dm

@@ -230,3 +230,5 @@
 	var/attack_icon_state //State for above
 
 	var/registered_z
+
+	var/list/progressbars = null //for stacking do_after bars

code/modules/surgery/surgery.dm

@@ -162,7 +162,7 @@
 				// Not staying still fails you too.
 				if(success)
 					var/calc_duration = rand(S.min_duration, S.max_duration)
-					if(!do_mob(user, M, calc_duration * toolspeed, zone))
+					if(!do_mob(user, M, calc_duration * toolspeed, zone, exclusive = TRUE))
 						success = FALSE
 						to_chat(user, "<span class='warning'>You must remain close to and keep focused on your patient to conduct surgery.</span>")