- 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 r281532 (by delphij): Eliminate unused headers.

MFC r273635, r273793, r274797: Add basic iSNS client to the iSCSI target.

This makes ctld(8) register its iSCSI targets and portals on configured
iSNS servers to allow initiators find them without active discovery.

Fetching of allowed initiators from iSNS is not implemented now, so target
ACLs still should be configured manually.

Relnotes: Yes
Sponsored by: iXsystems, Inc.

Add basic iSNS client to the iSCSI target.

This makes ctld(8) register its iSCSI targets and portals on configured
iSNS servers to allow initiators find them without active discovery.

Fetching of allowed initiators from iSNS is not implemented now, so target
ACLs still should be configured manually.

Reviewed by: trasz@
MFC after: 1 month
Sponsored by: iXsystems, Inc.