Whitespace.
Fix a regression introduced by r251967, resulting in:

/usr/libexec/bsdconfig/140.startup/startup: 130:
Syntax error: ";;" unexpected (expecting "fi")
Perform some code consolidation and replace nested case-statements with
more logical if-else statements for each menu selection.
Fix a gcc warning uncovered after r251745.

Reported by:	Sergey V. Dyatko
Reviewed by:	neel
Change the f_dialog_{yesno,noyes}() function-arguments in `dialog.subr' to
accomodate an $hline value for overriding the default. This change does
not effect any current modules as it turns out that not one single usage of
either f_dialog_yesno() or f_dialog_noyes() relied on accepting more than a
first argument (read: all occurrences quoted the first parameter; so $* was
never depended upon).

This will allow some custom invocations of --yesno and --noyes to roll over
to these functions (for example, in `timezone/timezone').
When I first wrote the timezone module, it was in sysutils/tzdialog and it
pre-dates bsdconfig. Update the code to take advantage of f_dialog_msgbox().
Take advantage of newly updated f_dialog_{yesno,noyes}() functions from
SVN r251977 (adding an $hline parameter).
Change a humongous if-statement at the end of f_install_zoneinfo_file() into
an early return, allowing a huge chunk of code to be indented one-level less
Remove extra whitespace lines.
Bandaid: mips doesn't seem to have the full set of atomics builtins.  I
will investigate more.
 - Persist the caller's flags in the bucket allocation flags so we don't
   lose a M_NOVM when we recurse into a bucket allocation.

Sponsored by:	EMC / Isilon Storage Division
When a previous call to sbsndptr() leaves sb->sb_sndptroff at the start of an
mbuf that was fully consumed by the previous call, the mbuf ptr returned by the
current call ends up being the previous mbuf in the sb chain to the one that
contains the data we want.

This does not cause any observable issues because the mbuf copy routines happily
walk the mbuf chain to get to the data at the moff offset, which in this case
means they effectively skip over the mbuf returned by sbsndptr().

We can't adjust sb->sb_sndptr during the previous call for this case because the
next mbuf in the chain may not exist yet. We therefore need to detect the
condition and make the adjustment during the current call.

Fix by detecting the special case of moff being at the start of the next mbuf in
the chain and adjust the required accounting variables accordingly.

Reviewed by:	andre
MFC after:	2 weeks
The SUSv4tc1 requires that pthread_setcancelstate() shall be not a
cancellation point.  When enabling the cancellation, only process the
pending cancellation for asynchronous mode.

Reported and reviewed by:	Kohji Okuno <okuno.kohji@jp.panasonic.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Some clarifications and updates for the comments, mostly retrieved
from Bruce Evans.  Trim the trailing spaces.

MFC after:	1 week
Fix an unfortunate typo with the compat shims

Obtained from:	Netflix
MFC after:	now
Use ICMP6STAT_INC() macro for ICMPv6 errors accounting.

MFC after:	2 weeks
Alphabetize includes.
Alphabetize reserved-word (resword) registration.
Whitespace and comments.
Whitespace.