Shared-Added RSSI fields to manualcontrol settings and command UAVO.
Flight-ManualControl module populate RSSI UAVO fields from PWM,PPM or ADC
Flight-UAVOMavlinkBridge send new RSSI value on mavlink stream
Flight-ManualControl Module-wrap ADC funcion call in #IFDEF
shared-manualcontrolsettings uavo-fix RssiMin/Max values
shared-manualcontrolsettings uavo-Added RssiPwmPeriod field
flight-modules-manualcontrol Handle new ManualcontrolSettings RssiPwmPeriod field

If the period is 0 use the value from the PWM driver directly.
If not 0 use the (measured positive pulse width) % (frame width)
formula.
This is a workaround to handle FrSky high frequency PWM RSSI.
Merge branch 'rssi_handling' of github.com:guilhermito/TauLabs into rssi_handling
Merge branch 'next' of git://github.com/TauLabs/TauLabs into rssi_handling

Conflicts:
	shared/uavobjectdefinition/manualcontrolsettings.xml
Merge pull request #839 from guilhermito/rssi_handling

Collect and use RSSI value.