- 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

MFC 281887:
Reassign copyright statements on several files from Advanced
Computing Technologies LLC to Hudson River Trading LLC.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

The output of perror(1) is now showing local messages for locales
supported by libc/nls

PR: bin/140499
Approved by: gnn@

Use prototype for usage(). This makes perror(1) WARNS=6 clean.

Approved by: gnn

A few more style changes as well as a more broad allowance for
errors to be given by the caller. Change output to be easier
for use in scripts.

Submitted by: bce

Fix a few style(9) nits.

Submitted by: danfe

Add a new program, perror, which takes an errno as a command line argument
and outputs the associated textual message in the same way that
perror(3) would if called within a program.