- 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

- Move jenkins.h to jenkins_hash.c
- Provide missing function that can do hashing of arbitrary sized buffer.
- Refetch lookup3.c and do only minimal edits to it, so that diff between
our jenkins_hash.c and lookup3.c is minimal.
- Add declarations for jenkins_hash(), jenkins_hash32() to sys/hash.h.
- Document these functions in hash(9)

Obtained from: http://burtleburtle.net/bob/c/lookup3.c

Fix a compiler warning so hash.h can be included in the kernel. This changes
the args for hash32_stre and hash32_strne but there are no consumers in the
base system and openbgpd does not use it which the initial import was for.

Silence on: hackers

Add missing "const" qualifiers.

Submitted by: bde

Revise markup.

Import OpenBSD's manual page to the sys/sys/hash.c functions imported two
days earlier.

Obtained from: OpenBSD