Pod Seeking Weaponry [Feature]

[Noah Buttes]

Note to coders:
Spoiler!

In the 2016 release, lines 344 and 345 of projectile_parent.dm don't account for the possibility of xo or yo actually being zero. This means that do_step will oftentimes cause a division by zero error runtime when using rotateDirection.
Example:

Code:

runtime error: Division by zero
proc name: do step (/obj/projectile/proc/do_step)
  source file: projectile_parent.dm,344
  usr: the buttface mcgee (as Osbert ... (/mob/living/carbon/human)
  src: the projectile (/obj/projectile)
  usr.loc: the floor (173,148,1) (/turf/simulated/floor)
  src.loc: null
  call stack:
the projectile (/obj/projectile): do step()
the projectile (/obj/projectile): process()
the projectile (/obj/projectile): launch()

This patch leverages pre-existing code to create pod-seeking explosive 40mm grenade rounds.

That's it.

I picture security using these to combat syndicate assault pods, but I imagine they'd have to be locked away in the armory.

Compare:
https://github.com/goonstation/goonstati...ker-missle

Diff:
https://github.com/goonstation/goonstati...issle.diff

Patch:
https://github.com/goonstation/goonstati...ssle.patch

[New525]

Cool!