- 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

Merge r257694 from head:

Remove remnants of BIND from /etc, since there is no BIND in base now.

Sorry, that would break users running head and BIND from ports, since
ports rely on these scripts. The ports will be fixed soon.

Approved by: re (kib)

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

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

Add support for backing up the old kernel when installing a new kernel
using freebsd-update. This applies to using freebsd-update in "upgrade
mode" and normal freebsd-update on a security branch.

The backup kernel will be written to /boot/kernel.old, if the directory
does not exist, or the directory was created by freebsd-update in a
previous backup. Otherwise freebsd-update will generate a new directory
name for use by the backup. By default symbol files are not backed up
to save diskspace and avoid filling up the root partition.

This feature is fully configurable in the freebsd-update config file,
but defaults to enabled.

MFC after: 1 week (stable/7)
Reviewed by: cperciva
Approved by: re (kib)

Add /usr/share/man/whatis, /var/db/locate.database, and /var/log to the
list of paths which `freebsd-update IDS` should ignore by default.

Make `freebsd-update IDS` not complain about /usr/share/man/cat* by
default.

Add /boot/device.hints to the list of files which will have local
modifications merged. I had initially expected that people would
put any local changes into /boot/loader.conf, but it turns out that
editing /boot/device.hints is something many people do.

Suggested by: Jaakko Heinonen
MFC after: 1 week

Add /root/, /.cshrc, and /.profile to the default UpdateIfUnmodified
directive. Users get irritated if FreeBSD Update steps on these while
upgrading to a new release.

MFC after: 3 days

Add support for "freebsd-update -r newrelease upgrade" -- binary
upgrading to new releases. Important parts of this code include
* automatically determining which optional components (e.g., src,
info, proflibs) are installed.
* merging changes in files which are modified locally and have
changed between the currently running and new release.
* prompting the user to rebuild all 3rd party software before
deleting old shared libraries.

Yes, this is compatible with "freebsd-update rollback" -- you can
test a new -BETA and roll back to the old release if you don't
like it.

Subject to re@ approval, this will be MFCed before 7.0-BETA3 and
6.3-RC1.

MFC after: 2 days

Add FreeBSD Update 2.0 client code. The build code is in the projects
repository.

Sponsored by: FreeBSD security development fundraiser