- 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

dhclient needs to have /var/empty and a _dhcp user
(it also needs /sbin/dhclient-script, will handle that later)

Fixup the /tmp directory permissions to 01777.

PR: misc/15875

Commit PicoBSD mega-patch:
. Bring PicoBSD up to date with -CURRENT reality.
. Make PicoBSD smart and not spam /dev/vn0 and /mnt. Now it uses the first
unused vn device and creates a temporary mountpoint in /tmp.
. Miscellaneous build cleanups and optimizations.

Unfortunately the bridge, isp, and router floppies are too big and need
the axe treatment. The install floppy needs updating to -CURRENT. Dial and
net build and (appear to) run OK. I will be adressing these in the
near future (unless someone beats me to it :-) ).

PR: misc/17737
Submitted by: Omachonu Ogali <oogali@intranova.net>

Add global version of mfs.mtree -- this is common to most floppy types

Approved-by: jordan