MFC r263811 (by trasz):
Remove ctl_mem_pool.{c,h}.
MFC r263979 (by trasz):
Hide CTL messages about SCSI error responses.  Too many users take
them for actual target errors.  They can be enabled back by setting
kern.cam.ctl.verbose=1, or booting with bootverbose.
MFC r264020 (by trasz):
Remove the homegrown ctl_be_block_io allocator, replacing it with UMA.
There is no performance difference.
MFC r264851

Eliminated optarg global being used outside of the function which called getopt

Sponsored by:	Multiplay
MFC r265150:
Do not reread SCSI disk VPD pages on every device open.

Instead of rereading VPD pages on every device open, do it only on initial
device probe, and in cases when device reported via UNIT ATTENTIONs that
something has changed.  Capacity is still rereaded on every open because
it is more critical for operation and more probable to change in run time.

On my tests with Intel 530 SSDs on mps(4) HBA this change reduces time
GEOM needs to retaste the device (that includes few open/close cycles)
from ~150ms to ~30ms.
MFC r264853

Add some new ATA defines for SATA 3.1 spec

Sponsored by:	Multiplay
MFC r264863

Add information about supported NCQ functionality to camcontrol identify.

Sponsored by:	Multiplay
MFC r264878

Increase ACPI_MAX_TASKS to be 4 x the number of CPU's as 2 x was still
insufficient on some machines.

Sponsored by:	Multiplay
MFC r265159:
Respect MAXIMUM TRANSFER LENGTH field of Block Limits VPD page.

Nobody yet reported disk supporting I/Os less then our MAXPHYS value, but
since we any way have code to read Block Limits VPD page, that is easy.
MFC r264849 & r264883

Exposed debug.acpi.max_tasks and debug.acpi.max_threads via sysctls so their
values can be viewed.

Sponsored by:	Multiplay