Plumb the cn_grab and cn_ungrab routines down into the uart
clients. Mask RX interrupts while grabbed on the atmel serial
driver. This UART interrupts every character. When interrupts are
enabled at the mountroot> prompt, this means the ISR eats the
characters. Rather than try to create a cooperative buffering system
for the low level kernel console, instead just mask out the ISR. For
NS8250 and decsendents this isn't needed, since interrupts only happen
after 14 or more characters (depending on the fifo settings). Plumb
such that these are optional so there's no change in behavior for all
the other UART clients. ddb worked on this platform because all
interrupts were disabled while it was running, so this problem wasn't
noticed. The mountroot> issue has been around for a very very long
time.

MFC after:	3 days
Move the installer's keymap solution introduced by SVN r259468. The new
location of /etc/rc.local on the install media is more appropriate as it
knows serial vs. non-serial and can also do the change earlier (so that
even the initial Install dialog can benefit from the change).

MFC after:	3 days
Document the lack of chflags support in pax(1)

PR:		docs/135516
Submitted by:	arundel (based on)
Approved by:	gjb (mentor)
gcc: warnings from -Wformat-security

Minor mismatch in r259666.

Obtained from:	Apple GCC 4.2 - 5646 (Radar 5764921)
MFC after:	1 week
Minor grammar fix

PR:		docs/185057
Submitted by:	Yuri (yuri@rawbw.com)
Approved by:	gjb (mentor)
Set the PMC trapframe macros appropriately

MFC after:	2 weeks
Consolidate the virtual apic initialization in a single function: vlapic_reset()
Add item for clang 3.3 update.
Add revision number for BIND removal.
Mention that GCC is not built on platforms where CLANG is the default system
compiler.
Add revision number for iSCSI initiator.
Mention TRIM support for ZFS.
Re-order ZFS items.
Add some revision numbers.
Mention ZFS zio nop-write improvement.
Mention addition of vmx(4).
drm: Lower priority of "EDID checksum is invalid" message

The priority goes from "error" to "debug".

Connectors are polled every 10 seconds. Reading EDID is part of this
polling. However, when an invalid EDID is returned, this error message
is logged. When using Newcons for instance, having a kernel message
every 10 seconds is getting annoying.

Now that it's a debug message, it'll be logged only if hw.dri.debug is
enabled. This fix console spamming for some users.

Tested by:	Larry Rosenman <ler@lerctr.org>
Mention virtio support.
Fix fallout from r258479: in pf_free_src_node() the node must already
be unlinked.

Reported by:	Konstantin Kukushkin <dark rambler-co.ru>
Sponsored by:	Nginx, Inc.
For gnu/lib/csu, only use gcc-specific flags when compiling with gcc.

MFC after:	3 days