- 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

Reconnect gdb info file to the build.

Submitted by: Szilveszter Adam <sziszi@bsd.hu>

Upgrade for readline 4.2

A bandaid to try and make this buildable. This should probably be
rechecked by somebody who knows what is meant to happen here. The new
libreadline rluser.texinfo file duplicates the '@defcodeindex bt' entry.

Oops, This should have been committed with the Makefile change that
requires the new file.

Fixed stale near-copy of contrib/libreadline/doc/hsuser.texinfo. Patch
it at build ntime, and only keep the patch for it here.

Don't keep a copy of contrib/gdb/gdb/doc/all-cfg.texi here. Link to it
at build time.