altq: Don't use poll cache

The poll/dequeue model is no longer applicable to SMP system, e.g.

   CPU-A            CPU-B
     :                :
   poll               :
     :              poll
   dequeue (+)        :

The dequeue at (+) will hit the poll cache set by CPU-B.

Reported-by: pavalos@
libc: Add strchrnul(), a glibc extension

* This function behaves like strchr() but returns a pointer to the
  terminating \0 byte of the string instead of NULL if the character
  was not found

* It was first implemented in glibc-2.1.1

Obtained-from: FreeBSD
kernel - Attempt to fix SMP races with ^T

* The ^T (ttyinfo()) code was still using critical-sections to protect
  its probe.  This no longer works.  Replace with appropriate hold's and
  tokens.

Reported-by: marino
kernel - Fix at least one 64-bit ddb backtrace issue

* Fix DDB support functions which were overflowing a 4-byte buffer when
  reading and writing 8-byte values.

Reported-by: tuxillo
strchr.3: Small wording fixes.
kernel - remove kprintf info about magazine capacity

This kprintf was added when the magazine capacity calculation was
modified (commit 765b1ae0159cca211559c3035641d842f28defd7).

While it only emits with verbose boot, the message can become quite a
nuisance with tmpfs mounts.  Running poudriere with verbose boot
effectively takes away the first virtual terminal.  This information
isn't very useful anymore, so get rid of it altogether.

Approved-by: dillon
kernel/pf: Fix a bunch of gcc47 -Waddress warnings.

The REASON_SET() macro is sometimes called with the address of a local
u_short instead of a pointer passed to the macro's caller. In its NULL
check, gcc47 detects that the address can never be NULL and issues a
-Waddress warning which part of -Wall.

To silence it, go via a u_short pointer in the macro. This fix is about
as harmless as the "issue" gcc47 was warning about.

While here, put two "x" parameters in parentheses.
kernel - Fix namecache hash list corruption

* Fix namecache hash list corruption.  A rare race is possible where
  a dummy namecache element used as a placeholder in hash list scans
  might be improperly removed by another cpu.

Reported-by: ftigeot
Merge branch 'master' into gsocdrm_jfree