-Adds CanPass() checks as needed to mulebots, now you can no longer use MULEs to bypass windows or flaps, and CanPass() checks are run for flaps when something is loaded, meaning you can't get on the MULE if it is under flaps

Fixes Issue 399

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@4351 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/machinery/bots/mulebot.dm

@@ -470,6 +470,9 @@
 
 	if(get_dist(C, src) > 1 || load || !on)
 		return
+	for(var/obj/structure/plasticflaps/P in src.loc)//Takes flaps into account
+		if(!CanPass(C,P))
+			return
 	mode = 1
 
 	// if a create, close before loading
@@ -517,7 +520,12 @@
 
 
 	if(dirn)
-		step(load, dirn)
+		var/turf/T = src.loc
+		T = get_step(T,dirn)
+		if(CanPass(load,T))//Can't get off onto anything that wouldn't let you pass normally
+			step(load, dirn)
+		else
+			load.loc = src.loc//Drops you right there, so you shouldn't be able to get yourself stuck
 
 	load = null