- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

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

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

Don't overwrite the global default CFLAGS when setting include paths.

MFC after: 3 days

* Add the readline(3) API to libedit. The libedit versions of
{readline,history}.h are in /usr/include/edit so as to not conflict with
the GNU libreadline versions. To use the libedit readline(3) one should
add "-I/usr/include/edit" to their Makefile
(spelled "-I${DESTDIR}/${INCLUDEDIR}/edit" within the FreeBSD source tree).

* Enable its use in the BSD licensed utilities that support readline(3).

* To make it easier to sync libedit development with NetBSD, histedit.h
is moved into libedit's directory as history shows shown we keep merging
it into that location.

Obtained from: NetBSD
Sponsored by: Juniper Networks

Switch the default WARNS level for sbin/ to 6.

Submitted by: Ulrich Spörlein

Finally bring in what was produced during Google SoC 2005:

Add functions to rename objects and to move a subdisk from one drive
to another.

Add manual page (finally).

Bring up-to-date the online help.

Obtained from: Chris Jones <chris.jones@ualberta.ca>
Sponsored by: Google Summer of Code 2005
MFC in: 1 week

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

For variables that are only checked with defined(), don't provide
any fake value.

Add gvinum, the geom_vinum userland tool.