GetTapePosition returned a non-zero partition number.
(mtinfo_drive::create_partitions): Reinitialize to partition 0.
Support TAPE_DRIVE_INITIATOR and TAPE_DRIVE_FIXED partitioning.
(mtinfo_drive::set_partition): Initialize new partition.
(mtinfo_drive::status): Readd accidentally dropped setting of mt_resid.
* net.cc (wsock_event::prepare): Always print debug output in case
of error.