- 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

Because ggatel(8) operates on local GEOM providers, use unlimited queue size in
GEOM GATE to fix the issue described in r220264. This also means that we no
longer need -q option, remove it. Don't bother to leaving it as a no-op, as
ggatel(8) is just an example utility.

Sort sections.

Added the EXIT STATUS section where appropriate.

Polish the mdoc(7) markup.

Add missing commands.

GEOM Gate local control utility.