replacing them with TAILQ's as appropriate. The SCSI code is the
first to be changed -- until the changes are complete, both b_act and
b_actf will be in the buf structure. b_actf will eventually be removed.
Added CONTROL device that only does user-ioctl and nothing else;
Added protection so user-ioctl requires write access;
Clean up scsiconf.h a little. It needs more work.