Open the uart emulation's backing tty in non-blocking mode.
This fixes the issue of bhyve appearing to halt when using
nmdm ports for the console, until a connection is made to
the other end.

bhyveload already does this.

Reported by:	Many.
MFC after:	3 weeks.
Add driver for Port control and interrupts (PORT).

PORT is responsible for external interrupts management,
so move IRQ lines from GPIO driver.
Fix support for increased logical sector size (4K-native drives).

- Logical sector size is measured in words, not bytes.
- If physical sector is not bigger then logical sector, it does not mean
it should be set equal to 512 bytes, but set to logical sector.

PR:		misc/187269
Submitted by:	Ravi Pokala <rpokala@panasas.com>
MFC after:	1 week
libc man pages: Remove reference to non-existent FreeBSD Security
Architecture

MFC After:	3 days
- Export panel info to DTS
- Reset all the layers before setup first one
- Enable display
wlanstats: Add some logic to translate from a vap to its parent device.

This isn't entirely correct (as the device may not necc. be called wlan*) but
this will be further worked into a combined ath, iwn, wlan, etc. tool.

Discussed with:	jhb, adrian
kern/Makefile
	Set WARNS=5 for all files in this directory

kern/unix_seqpacket_test.c
	Fix compiler warnings.  Most were benign, but rcvbuf_oversized
	wasn't working as intended because I forgot to set the buffer sizes.

MFC after:	2 weeks
Reported by:	pho
Sponsored by:	Spectra Logic Corporation
Allow dispatched reswords to carry arguments. Fix a comment while here.
Add missing local declaration.
Fix a typo in a comment.
Fix incorrect return status if var_to_set and var_to_get are the same.
Make f_show_err non-fatal.
Centralize function name. Update a comment while here.
s/__number/__num/ for code clarify but more to prevent localization of
__number if passed as the var_to_set argument.
Comment -- to go with NL global introduced (but not mentioned) by r262901
Fix the arm sys_sigreturn(): its argument is a struct ucontext, not a
struct sigframe containing the struct ucontext.

The signal trampoline return code on the other hand DOES have just a
struct sigframe on the stack to work with, so have it get a pointer to
the ucontext out of there to pass along to sys_sigreturn.

In other words, make everything work right whether sys_sigreturn is
invoked from the trampoline or from userland code calling sigreturn(2).

Submitted by:	Takashi Komatsu <komatsu.taka@jp.panasonic.com>
Reviewed by:	cognet
Rewrite groupmgmt -- hooking it into the scripting system with dispatch
commands groupAdd, groupDelete, and groupEdit. Getting rid of the awkward-
to-use `groupinput' bolt-on which Ron and I talked about rewriting.
Strip arm/conf/DEFAULTS down to just items that are mandatory for running
the architecture.  Move the other contents into each of the individual
config files.

Requested by:	imp
Change dipatch words from group* to *Group to backward compatible with
ye-olden sysinstall(8).
Fix copy/paste error in a comment.