- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r260695, r260696, r260884, r260885, r260886, r260887

Provide a simplified way to specify GPIO pins for the Atmel port.

Add at91 data so we can convert a PIO unit number into a base address.

Add at91 standard memory controller helper functions.

Generalize AT91 NAND support a bit.

Connect NAND for the SAM9260EK eval board, as well as the HotE HL-201.

Add nand device and NANDFS into the mix for those at91 boards that have
support for it at the moment.

Add standard memory controller helper functions.