TradHeli: make output_test, move_swash and reset_swash private

moved the implementation of these methods around in .cpp file to match
.h file
TradHeli: formatting and param description changes
TradHeli: bugfix to update swash in run_rate_controllers
TradHeli: add get_pilot_desired_collective

Perhaps this should be moved to the main code's heli.pde sketch
TradHeli: add THROTTLE_MANUAL_HELI

Move check_dynamic_flight to run as scheduled task
Copter: initialise roll, pitch, yaw modes to stabilize

This fixes a bug in which the stabilize throttle controller would be
non-tilt compensated until the user switched to another flight mode and
back again
TradHeli: add landing collective min
TradHeli: use landing collective when landed or landing