PLOCK - Pre-Lock, Planet Drop Mode
        Locks onto a Fig'd Sector and engages the Planetary-
        Warp when the Fighter(s) are removed, or a Mine is
        tripped.

        plock [sector (0 for plock stop) ] {kill} {Delay}.

         -  [kill]  = Citkill right after successful firing
         -  [Delay] = Delay to launch Plock
