- 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

64-bit clean + WARNS=6:
- Convert the (char *) cast+cast backs magic to
memcpy(3). Without this, the resulting code
is potentially risky with higher optimization
levels.
- Avoid same name when calling local variables,
as well as global symbols. This reduces
confusion for both human and compiler.
- Add necessary casts, consts
- Use new style function defination.
- Minor style.Makefile(5) tweak
- Bump WARNS?= from 0 to 6

** for the aout code: changes are intentionally limited
to ease maintaince.

Restore these files to make ldconfig(8) happy.