Updates blob

Remains of player blob axed.
blob_act() axed. Blob now has an arbitary set of things it can attack.
It will flow over everything else. Blob has an awful tendency to destroy
non-craftables.
Will test more tomorrow.
Blob will now attack mechs.
Fixes #8106.
Fixes #10705.

code/game/objects/effects/aliens.dm

@@ -77,11 +77,6 @@
 	healthcheck()
 	return
 
-/obj/effect/alien/resin/blob_act()
-	health-=50
-	healthcheck()
-	return
-
 /obj/effect/alien/resin/hitby(AM as mob|obj)
 	..()
 	for(var/mob/O in viewers(src, null))

code/game/objects/effects/chem/foam.dm

@@ -150,9 +150,6 @@
 /obj/structure/foamedmetal/ex_act(severity)
 	qdel(src)
 
-/obj/structure/foamedmetal/blob_act()
-	qdel(src)
-
 /obj/structure/foamedmetal/bullet_act()
 	if(metal == 1 || prob(50))
 		qdel(src)