- 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

Remove the "funny targets" make check. We no longer need embedded :: targets
to build FreeBSD (they are used in Perl man pages). We never needed embedded
"!" in targets that I can find.

We got this from OpenBSD and I cannot find any other make that supports
such things -- contrary to their commit message claim: "This behaviour
is also consistent with other versions of make.".