- 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 r268838, r277644:

Add support for Toradex Apalis i.MX6 development board.

Add support for imx6 audio transmitting, include drivers for:
o Digital Audio Multiplexer (AUDMUX)
o Smart Direct Memory Access Controller (SDMA)
o Synchronous Serial Interface (SSI)

Add support for audio transmitting, include drivers for:
o Digital Audio Multiplexer (AUDMUX)
o Smart Direct Memory Access Controller (SDMA)
o Synchronous Serial Interface (SSI)

Disable by default as it depends on SDMA firmware.

Sponsored by: Machdep, Inc.