Percent-ships-destroyed

percent-ships-destroyed
        Boolean function which returns true if the percentage of ships in the listed ships and wings which have been destroyed
is greater or equal to the given percentage.  For wings, all ships of all waves are used for calculation for the total possible
ships to be destroyed.

Takes 2 or more arguments:
        1:      Percentge of destroyed ships at which this function will return true.
        2+:     List of ships/wing whose destroyed status should be determined.