- 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 r267355:
Add UUIDs for DragonFlyBSD's partition types.

MFC r267356:
Add DragonFlyBSD's Hammer FS types and type names.

MFC r267357:
Add aliases for DragonFlyBSD's partition types.

MFC r267358:
Allow dumping to DragonFlyBSD's swap partition.

MFC r267359:
Add disklabel64 support to GEOM_PART class.

This partitioning scheme is used in DragonFlyBSD. It is similar to
BSD disklabel, but has the following improvements:
* metadata has own dedicated place and isn't accessible through partitions;
* all offsets are 64-bit;
* supports 16 partitions by default (has reserved place for more);
* has reserved place for backup label (but not yet implemented);
* has UUIDs for partitions and partition types;

MFC r267360:
Add disklabel64 support

Relnotes: yes

Add disklabel64 support to GEOM_PART class.

This partitioning scheme is used in DragonFlyBSD. It is similar to
BSD disklabel, but has the following improvements:
* metadata has own dedicated place and isn't accessible through partitions;
* all offsets are 64-bit;
* supports 16 partitions by default (has reserved place for more);
* has reserved place for backup label (but not yet implemented);
* has UUIDs for partitions and partition types;

No objections from: geom
MFC after: 2 weeks
Relnotes: yes