- 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

General mdoc(7) and typo fixes.

PR: 167734
Submitted by: Nobuyuki Koganemaru (kogane!jp.freebsd.org)
MFC after: 3 days

Spelling fixes.

mdoc: order prologue macros consistently by Dd/Dt/Os

Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.

Reviewed by: ru
Approved by: philip, ed (mentors)

Document the additional error returns possible when handling ELF objects
that require extended numbering.

Fix minor formatting issues:

- make document title match filename;
- remove hard sentence breaks, whitespace at EOL, and double whitespace;
- sort SEE ALSO xrefs, adding missing section numbers;
- fix a misspelled macro name.

MFP4: Add an implementation of the ELF(3) and GELF(3) API set.

Bump __FreeBSD_version.

Reviewed by: jb