Copter: only report gps glitch when usb disconnected
Copter: add RC_FEEL_RP parameter

Values from 0 ~ 100 control amount of filtering on roll and pitch input.
100 = no filter so crisp feel, 0 = a lot of filtering so very sluggish
response
Copter: firmware to AC3.1.2-rc2
Copter: firmware to AC3.1.2
AP_Motors: properly constrain thr_adj_max
Copter: AC3.1.3 release notes
Copter: version to AC3.1.3