Copter: update Release notes for AC3.1-rc1 again
Build: sort .gitignore alphabetically, add .bin
PX4: start rgbled driver
AP_Notify: add radio and battery failsafe

radio and battery failsafe are slow flashing yellow
pre-arm check failure changed to double flashing yellow
Copter: integrate AP_Notify batt and radio failsafes
Sprayer: add pump min rate and test

If pump is enabled while copter is disarmed it will spray as if
travelling at 1m/s
Copter: integrate sprayer pump test
AP_SteerController: move scaler onto integrator input

this should make integrator scale with speed

Pair-Programmed-With: Paul Riseborough <p_riseborough@live.com.au>
AP_Airspeed: reduce speed of autocal 

it was responding to noise too rapidly

Pair-Programmed-With: Paul Riseborough <p_riseborough@live.com.au>
Rover: changed default L1 period to 11
Rover: added SR0 and SR3 stream rates to auto docs
param_metadata: support .pde files for parameter autodocs
Copter: fixed SR0 and SR3 autodocs
Plane: fixed SR0 and SR3 autodocs
autotest: fixed handling for wiki and xml generation
AP_HAL: added voltage_latest() interface

this will be used for reading the 5V rail
AP_HAL_AVR: support voltage_latest()
HAL_PX4: support all analog input pins, with scaling

this allows voltage/current/Vcc sensing on FMUv2
Rover: fixed Vcc
Copter: fixed Vcc