packet-cd

Fixes for some buggy logic to abort nicely where possible, buffer_head reference bugfixes, /proc layout changes to per-write file, setting quiet bit on write cache disabling (some drives don't support it), a new recovery mode, and starting bad block remapping (always piggy buffers to maintain b_end_io consistency).

This release fixes a pkt_put_buffer compile error, a linking error on
modular CDROMs and builtin packets, a problem with SCSI_DEBUG_QUEUES,
and problems with the help entries. It merges 2.4.4 final, removes
throttling code, correctly kills requests on I/O errors, and doesn't
clear BH_Uptodate for failed writes.

Default speed moved from 8 to 16 speed. Various bugfixes.

Fixes for the data corruption issue that plagued release 'b' and 'c' and a whole heap of other bugs.

SCSI CD-RW works again. Typos in io_request_lock were fixed. pkt_sem is now grabbed before invoking pkt_handle_queue. SCSI now uses queuedata to mirror pd->queuedata. SCSI sr debug messages were removed. Empty block querying was activated (though it requires CVS UDF, CDRW branch).