& @lock evaluation2

  Examples:
    > @lock bank=checkmoney/1
    > &checkmoney bank=[gt(money(%#),5000)]
    Only people and objects with more than 5000 pennies may pass.
    Note: this lock requires wizard privileges to read the worth of 
    other players.
 
    > @lock divisible_by_five_club = checkdiv/0
    > &checkdiv divisible_by_five_club = [mod(mid(%#,2,20),5)]
    Only objects whose db-number is divisible by 5 may pass.
  See also: @lock attributes.