Ifacetype$ ()

   Synopsis:
      Returns the type of the current interface notification

   Notes:
      The interface notification list contains all the notifications received,
         and not yet processed, as the result of an earlier SETTRIG, SETALIAS,
         SETMACRO, SETTIMER or SETHOOK statement.
      Returns one of the following strings: "trigger", "alias", "macro",
         "timer", "hook" or an empty string, if there is no current
         notification.
