- 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 r285050, r285053, r285059:

When passwd or group information is changed (by pw, vipw, chpass, ...)
temporary file is created and then a rename() call move it to official file.
This operation didn't have any check to make sure data was written to disk
and if a power cycle happens system could end up with a 0 length passwd
or group database.

There is a pfSense bug with more information about it:

https://redmine.pfsense.org/issues/4523

The following changes were made to protect passwd and group operations:

* lib/libutil/gr_util.c:
- Replace mkstemp() by mkostemp() with O_SYNC flag to create temp file
- After rename(), fsync() call on directory for faster result

* lib/libutil/pw_util.c
- Replace mkstemp() by mkostemp() with O_SYNC flag to create temp file

* usr.sbin/pwd_mkdb/pwd_mkdb.c
- Added O_SYNC flag on dbopen() calls
- After rename(), fsync() call on directory for faster result

* lib/libutil/pw_util.3
- pw_lock() returns a file descriptor to master password file on success

Differential Revision: https://reviews.freebsd.org/D2978
Approved by: re (kib), bapt (implicit agreed)
Sponsored by: Netgate

MFC r261824:
libutil/pw_util.3: Fix two prototypes.

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

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

Fix typo

Correct attribution.

Minor mdoc and language fixes.

Removed unnecessary bits in the header that shows where I stole the template

Document the pw_util(3) functions

Reviewed by: des, gjb