- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

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

MFC 258063,258064,258066,258097,258185,259134:
- Add an -s option to the regression tests that specifies a path to an
alternate etcupdate.sh script to test. This allows a non-installed
version of the script to be tested more easily.
- Add a pre-world mode of updating similar to the -p option that can be
passed to mergemaster.
- Fix a couple of issues with -F:
- Fix ALWAYS_INSTALL to take precedence over the FreeBSD ID checks.
- Fix the -F option in the case that the only upstream change is a
change in the FreeBSD ID and the local file is removed.
- Refresh /etc/localtime after each update using tzsetup -r.
- Regenerate /var/db/services.db when /etc/services changes.

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

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

The etcupdate utility is a tool for managing updates to files that are
not updated as part of `make installworld' such as files in /etc. It
manages updates by doing a three-way merge of changes made to these files
against the local versions. It is also designed to minimize the amount
of user intervention with the goal of simplifying upgrades for clusters
of machines.

The primary difference from mergemaster is that etcupdate requires less
manual work. The primary difference from etcmerge is that etcupdate
updates files in-place similar to mergemaster rather than building a
separate /etc tree.

Requested by: obrien, kib, theraven, joeld (among others)