Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove ISDN4BSD (I4B) from HEAD as it is not MPSAFE and
parts relied on the now removed NET_NEEDS_GIANT.
Most of I4B has been disconnected from the build
since July 2007 in HEAD/RELENG_7.

This is what was removed:
- configuration in /etc/isdn
- examples
- man pages
- kernel configuration
- sys/i4b (drivers, layers, include files)
- user space tools
- i4b support from ppp
- further documentation

Discussed with: rwatson, re

Expand *n't contractions.

Mechanically kill hard sentence breaks and double whitespaces.

Ispell sweep of share/man/man4.

mdoc(7) police: markup nits.

Document the change from 0.0.0.1 to 0.0.0.* as `any remote address is OK'.

MFC after: 1 month

Document that we now implement VJ header compression.

pseudo-device -> device in kernel config lines. Removed whitespace at EOL.
Reviewed by: joerg, dd

mdoc(7) police: split punctuation characters + misc fixes.

mdoc(7) police: do not split author names in the AUTHORS section.

Avoid use of direct troff requests in mdoc(7) manual pages.

Supply only one author name per instance of %A, as per mdoc.samples(7).

PR: 18465
Submitted by: Kazu TAKAMUNE <takamune@avrl.mei.co.jp>

Remove ``count'' argument of the pseudo-devices that do not
use it anymore.

$Id$ -> $FreeBSD$

Spelling fixes.

Submitted by: Josh Gilliam <josh@quick.net>
PR: 6880

.Sh AUTHOR -> .Sh AUTHORS according to mdoc specs.
Use .An/.Aq.

Make it possible to indicate that we don't care about the remote
sides IP address, as long as it isn't 0.0.0.0

Update to match reality. PAP/CHAP are now implemented, a number of bugs
fixed as well.

Sort cross refereces in section SEE ALSO.

Add a man page for sppp(4).