Makes Telescience portals more accurate, fixing a number of issues (#7245)

Telescience portals now have a precision of 0, meaning they output on the turf the portal is on.
This means echoes can once again be reliably placed back into their bodies.
This also means calibration should hopefully result in 1/4 the explosions.
If you don't like GPS units phasing into walls and blowing you up 90% of the time, this is the PR for you

code/game/objects/effects/portals.dm

@@ -8,6 +8,7 @@
 	var/failchance = 5
 	var/obj/target = null
 	var/creator = null
+	var/precision = 1
 	anchored = 1.0
 
 /obj/effect/portal/CollidedWith(mob/M as mob|obj)
@@ -22,13 +23,15 @@
 	set waitfor = FALSE
 	src.teleport(user)
 
-/obj/effect/portal/New(loc, turf/target, creator=null, lifespan=300)
+/obj/effect/portal/New(loc, turf/target, creator=null, lifespan=300, precise = 1)
 	..()
 	src.target = target
 	src.creator = creator
 
 	if(lifespan > 0)
 		QDEL_IN(src, lifespan)
+	
+	precision = precise
 
 /obj/effect/portal/proc/teleport(atom/movable/M as mob|obj)
 	if(istype(M, /obj/effect)) //sparks don't teleport
@@ -45,4 +48,4 @@
 			src.icon_state = "portal1"
 			do_teleport(M, locate(rand(5, world.maxx - 5), rand(5, world.maxy -5), 3), 0)
 		else
-			do_teleport(M, target, 1) ///You will appear adjacent to the beacon
+			do_teleport(M, target, precision)