Remove unneeded argument from shed_loose_parts
Alternators generate, and power cables send power.

Note that this makes alternators always consume the full amount of
engine power they can. This is almost always such a small amount that it
shouldn't be noticeable, but it *is* a little bit of extra fuel over
time.
Save the new vehicle_part target field.

And load it when we load the game. Silly dummy Narc.
Power cables drain power (from remote vehicles)

Also, removed some debug stuff. This seems to be working now.