sg: 16-byte cdb support and lots of fixes

sg: 16-byte cdb support and lots of fixes

-- Fixed prob with queue depths > 1 (usually would work at qd = 2,
   but had fundimental prob with retrieving multiple events)
   Only works up to QD 16 due to kernel limitation.

-- Fix problem with check and report scsi operation errors.
   There was no check, so op errors were being ignored.
   Added support to retrieve and print sense data to output.

-- Fix problem with op timeouts. No timeouts op time out was being set.
   Hardcoded to 30 seconds.

-- Support switch to 16 Byte operations when LBA range needed.

-- Set default size based on maxlba of device retrieved
   from ReadCapacity command.

Updated by Jens to:

- ->errdetails() must be reentrant. Return an allocated buffer, have
  the caller free it when done.

- Bump io engine version number, the ops have changed.

- Add strlcat() as a real helper, don't stuff it in sg.c

- Lots of style cleanups

Signed-off-by: Jens Axboe <axboe@fb.com>