fix bug with infinite loop in ShipDestroyer

the ShipDestroyer would get into an infinite loop when its tracking
a ship, but the ship has moved
add metadata when targeting a ship

dont just say the expected location of the ship, give metadata.
the ship mover needs to know if the expected location is known
(ie: its attacking it), its found SOMETHING (ie: scan result),
or a best guess. this is important when deciding where to move
the ships.