EFUN shutdown()
SYNOPSIS
     void shutdown();
DESCRIPTION
     This function shuts down the driver in a controlled  fashion
     (as  opposed  to how a crash would shut it down). Obviously,
     shutdown() is a sensitive function and should be secured.  
     Note: All creators have the command 'shutdown'. Security
     level SEC7 (70) and above it will occur immediately,
      otherwise it is timed for 5 minutes.