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
Plane: fixed Vcc
AP_ADC_AnalogSource: fixed APM1 build
Rover: update battery pin docs
Copter: allow Vcc checks on Pixhawk
Copter: update battery pin docs
Plane: update battery pin docs
PX4: support getting servorail voltage from ORB
SITL: fixed Vcc voltage
autotest: small adjustment to rover parameters
Sprayer: minor change to flags type
Copter Motors: add slow start feature

Combined armed, frame orientation and slow_start into flags bitmask
Removed ability to set max throttle because it was never used
Re-ordered class variables
Copter: removed calls to set motor's max throttle
Copter: integrate slow start feature