Revert "Refactored, simplified access system a bit.  Tested, for once."

This reverts commit a5e65d9b2b0d741fa2cb5ed7242975dd998f66b1.
Objects being pulled will transition with mobs changing Z-levels via space
-Added checks to prevent the nuke disk from leaving z1
-If the disk is deleted while it's inside a nuke, the nuke will lock itself

Conflicts:
	code/game/gamemodes/nuclear/nuclearbomb.dm
	code/game/turfs/space/space.dm
Merge pull request #150 from ZomgPonies/master

Hotfix