- 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 r290710, r291694, r291699 and r291793:
- Fix print formatting compile warnings for Sparc64 and PowerPC platforms.
- Updated the mlx4 and mlxen drivers to the latest version, v2.1.6:
- Added support for dumping the SFP EEPROM content to dmesg.
- Fixed handling of network interface capability IOCTLs.
- Fixed race when loading and unloading the mlxen driver by applying
appropriate locking.
- Removed two unused C-files.
- Convert the mlxen driver to use the BUSDMA(9) APIs instead of
vtophys() when loading mbufs for transmission and reception. While at
it all pointer arithmetic and cast qualifier issues were fixed, mostly
related to transmission and reception.
- Fix i386 build WITH_OFED=YES. Remove some redundant KASSERTs.

Sponsored by: Mellanox Technologies
Differential Revision: https://reviews.freebsd.org/D4283
Differential Revision: https://reviews.freebsd.org/D4284

MFC r272027:

Hardware driver update from Mellanox Technologies, including:
- improved performance
- better stability
- new features
- bugfixes

Supported HCAs:
- ConnectX-2
- ConnectX-3
- ConnectX-3 Pro

NOTE:
- TSO feature needs r271946, which is not yet merged.

Sponsored by: Mellanox Technologies
Approved by: re, glebius

Hardware driver update from Mellanox Technologies, including:
- improved performance
- better stability
- new features
- bugfixes

Supported HCAs:
- ConnectX-2
- ConnectX-3
- ConnectX-3 Pro

Sponsored by: Mellanox Technologies
MFC after: 1 week