  plexit(message)
  ***************

  plexit

  This routine is called in case an error is encountered during execution
  of a PLplot routine. It prints the error message, tries to release
  allocated resources, calls pl_exit and then exits. If cleanup needs to be
  done in the driver program then the user may want to supply his/her own
  version of pl_exit.

  message (char *, input): Error message.

