- (tcq, general) Remove the 'attempt to keep queue full option'. It worked
   on some IBM models, but failed miserably on others. Also removes some
   uglies in ide_queue_commands()

 - (tcq0 Change default depth back to 32.

 - (general) Add isr for no-dataphase taskfile, like task_no_data_intr but
   doesn't complain about failure. This is handy for commands what we _know_
   will fail, such as WIN_NOP.

 - (general) ide_cmd_type_parser() must set a handler to WIN_NOP... Otherwise
   we will just hang the ide system issuing a nop.

 - (general) HWGROUP(drive)->rq->special -> IDE_CUR_AR(drive)

 - (general) Have ide_raw_taskfile() copy back the taskfile after execution,
   otherwise we cannot use the info that ide_end_drive_cmd() puts in
   there.

 - (tcq) Use nIEN bit correctly in ide-tcq

 - (tcq) Small ide_tcq_wait_altstat() changes. Do initial 400ns delay (1us
   here), then 10us each successive run.

 - (tcq) Add beginning for 'nop auto poll' support check.

 - (tcq) Arm handler before GET_STAT() service check in
   ide_dma_queued_start, WD seemed to trigger interrupt before that.
   Makes WD Expert drives work with tcq.