- 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 r275681:

Add "-media" autofs map, to access data on removable media, such as CD
drives or flash keys. It can be enabled by uncommenting a single entry
in default /etc/auto_master. It can also be easily modified to use
fuse-based filesystems instead of in-kernel ones.

There is still one deficiency - the mountpoints are permanent, they
don't disappear when user removes the media. Fixing it needs some
autofs changes.

Relnotes: yes
Sponsored by: The FreeBSD Foundation

Add "-media" autofs map, to access data on removable media, such as CD
drives or flash keys. It can be enabled by uncommenting a single entry
in default /etc/auto_master. It can also be easily modified to use
fuse-based filesystems instead of in-kernel ones.

There is still one deficiency - the mountpoints are permanent, they
don't disappear when user removes the media. Fixing it needs some
autofs changes.

Differential Revision: https://reviews.freebsd.org/D1210
MFC after: 1 month
Sponsored by: The FreeBSD Foundation