message outs should now work correctly (including retransmissions).
Multiple messages ins should be more efficient. Missing REQ after
reselection phase should now (correctly) cause a wait with ENREQINIT
set.
* Abstract out the reselection out sequence, and use it directly to
get sense info. (This is somewhat faster than the generic done/sched
sequence.)
* If there are no ACBs available, wait interruptibly for one.
* Leave the interrupt registers alone during message in/out; just
watch for phase change. Don't (incorrectly) reenable interrupts
during data in/out; defer that to aicintr().
* Handle command pointer per SCSI 2 spec.
* Other minor coding improvements.
mycroft