Implement ABORT TASK SET and I_T NEXUS RESET task management functions.

Use the last one to terminate active commands on iSCSI session termination.
Previous code was aborting only commands doing some data moves.
Improve support for Intel Lynx Point USB 3.0 controllers by masking
the port routing bits like done in Linux.

MFC after:	1 week
Tested by:	Tur-Wei Chan <twchan@singnet.com.sg>
When new connection comes in, check whether we already have session from
the same intiator (Name+ISID).  If so -- terminate the old session and let
the new one take its place, as required by iSCSI RFC.
Correction to r268356: collide only sessions to the same target.
Optim and Fix for mge driver:
- add missing rcvif in mbuf
- add missing ipacket stat
- remove uncessary mbuf copy on output path
- fix deadlock of the TX engine in case of error

Obtained from:	NETASQ
MFC after:	2 weeks
Fix bugs for PERSISTENT RESERVE OUT bits in r268096.
Teach ctl_add_initiator() to dynamically allocate IIDs from pool.

If port passed negative IID value, the function will try to allocate IID
from the pool of unused, based on passed wwpn or name arguments.  It does
all its best to make IID unique and persistent across reconnects.

This makes persistent reservation properly work for iSCSI.  Previously,
in case of reconnects, reservation could be unexpectedly lost, or even
migrate between intiators.
Add support for READ FULL STATUS action of PERSISTENT RESERVE IN command.
Fix "use after free" on port creation error in r268291.
Don't call crdup nor uifind under vnode lock.

A locked vnode can get into the way of satisyfing malloc with M_WATOK.

This is a fixup to r268087.

Suggested by:	kib
MFC after:	1 week
Regenerate src.conf.5, which was completely busted by r268351.
Document C_HARDCLOCK flag.
Make XPT_GET_TRAN_SETTINGS to report CAM that command queueing is enabled,
but make couple changes to handle non-queued commands too, if happen.

MFC after:	2 weeks
Declaration whitespace changes for style(9).

MFC after:	1 week
Naughty NANDFS was using hidden unused flag, hiding the fact that the
flag was used and wasn't really available. Change the name without
fixing any laying issues that might be present in NANDFS' use of this
flag.
Fix typo in flag name.
rm -rf can fail sometimes with an error from fts_read. Make it honor
fflag to ignore fts_read errors, but stop deleting from that directory
because no further progress can be made.

When building a kernel with a high -j value on a high core count
machine, during the cleanobj phase we can wind up doing multiple rm
-rf at the same time for modules that have subdirectories. This
exposed this race (sometimes) as fts_read can return an error if the
directory is removed by another rm -rf. Since the intent of the -f
flag was to ignore errors, even if this was a bug in fts_read, we
should ignore the error like we've been instructed to do.
xdev builds libsupc++ and libstdc++ in a slightly strange way. This
cause a race to be exposed between the two. Compensate for this race
by serializing the build/install of libstdc++ before libsupc++.
Typo means that this couldn't have possibly fixed anything, so revert
r268377.
Make synopsis version of -3 flag match other uses in the page.

MFC after:	1 week