- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
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