Added welding rig, getting weird bug

So I added in the code for the welding rig, and it kinda works.  The
problem is, it only works if you've dropped an item in the welding rig.
Otherwise, you just get the "you can't do that while onboard!" message
it gives you when you try to examine a vehicle while in it.  Also, if
you do drop an item in the welding rig, it lets you examine the vehicle
even if you're onboard.  I'm not quite sure what's causing this, I'm
probably missing a ; or a , somewhere.  I'll try and look at this again
tomorrow, but if someone could glance at this and see what boneheaded
thing I missed, it would really help.