to be set when variable blocksize mode is on.
* fhandler_raw.cc: Eliminate `\n' from trace output.
(clear): Set `varblkop' to 0.
(dup): Copy varblkop as well.
(writebuf): Care for variable blocksize.
(open): Ditto.
(raw_read): Ditto.
(raw_write): Ditto.
* fhandler_tape.cc (open): Ditto.
(ioctl): Ditto. Some cleanups.