specify device logical blocksize.
Furthermore, it also adds an 'immediate' option, which then sends more modern
devices into formatting in the background. scsictl still waits around and
sends a TEST UNIT READY every 10 seconds and, based upon the sense data
it gets back after the invariable CHECK CONDITION, prints out a progress
indicator (based upon SKSV progress in the sense data).
While we're at it, add a 'tur', 'reserve', 'release', 'start' and 'stop'
functions to the device commands.
Fix a long standing bug in scsi_command- the value in retsts is an integral
value- not a bitmask.
mjacob