- 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

Revise markup in recently added manpages.

Fix typo in manual page reference.

Approved by: cognet (mentor)
MFC after: 3 days

Add a64l(), l64a(), and l64a_r() XSI extentions. These functions convert
between a 32-bit integer and a radix-64 ASCII string. The l64a_r() function
is a NetBSD addition.

PR: 51209 (based on submission, but very different)
Reviewed by: bde, ru