- 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 r257543, r264912, r264972, r264982 and r266472:
- Add preliminary support for the Realtek RTL8188EUS and RTL8188ETV chipsets.
- Add device ID for 'Sanoxy 802.11N' USB
- Initialize rssi variable.
- Fix gcc build, initialize off variable.
- The DELAY() should not be used in USB drivers.
- The usb_pause_mtx() function takes ticks and not milliseconds as last argument.

Add preliminary support for the Realtek RTL8188EUS and RTL8188ETV chipsets.

Committed over the TP-LINK TL-WN725N v2 (RTL8188EUS) on amd64 with WPA.