-Made tracking Cyborgs smoother by depending on their cameras first, and then checking to see if they're in camera vision.

-Corrosive Acid will check it still has a target before performing a tick. Made them a tiny bit quicker too, I wish they would take the time depending on w_class and or if anchored.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@4616 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/objects/effects/aliens.dm

@@ -296,6 +296,8 @@ Alien plants should do something if theres a lot of poison
 	var/ticks = 0
 
 /obj/effect/alien/acid/proc/tick()
+	if(!target)
+		del(src)
 	ticks += 1
 	for(var/mob/O in hearers(src, null))
 		O.show_message("\green <B>[src.target] sizzles and begins to melt under the bubbling mess of acid!</B>", 1)
@@ -307,7 +309,7 @@ Alien plants should do something if theres a lot of poison
 		del(target)
 		del(src)
 		return
-	spawn(rand(200, 600)) tick()
+	spawn(rand(200, 400)) tick()
 
 /*
  * Egg