- 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 r276004: Fix the indentation to simplify comparing the ARM config files.

MFC r276003:

Start to clean up the armv6 kernel configs by reducing the diff between
them in the first sections and the later FDT support.

MFC r271220:

Create a common i.MX53 config and use it with the two existing i.MX53 boards.

Create a common i.MX53 config and use it with the two existing i.MX53
boards.

This is just intended to split the common config entries out, further
cleanup is expected.

Reviewed by: ian@, rpaulo@ (earlier version)
Differential Revision: https://reviews.freebsd.org/D731