Various Fixes/Tweaks to Ninja

Ninjas now actually put a tech disk in their suit when they put it in
your suit. The code was silly and forgot to move the disk inside your
suit when you slotted it in. I fixed some things your death implant pull
request reverted. (SpiderOS things, mainly.), and did some tweaks to the
Spawn Ninja admin verb so we can now specify if we want a random or
preset player, and a random or preset mission to be assigned to the
Ninja.