[rotorcraft] improve in_flight detection heuristic

Simply checks if thrust, speed and acceleration are above a threshold.
Does not rely on RC thrust command anymore, but only on actual thrust command.
Not tested on real vehicle at all so far...

Attempt to improve issue #201 and replaces #468
[rotorcraft] set guidance_v_zd_sp to zero in altitude hold for visualization
[math] add FLOAT_QUAT_OF_ORIENTATION_VECT
[rotorcraft][guidance][stabilization] quat setpoint fixes

Don't pretend that the commands from guidance_h are actually real euler angles.
Compose a roll/pitch quaternion from simultaneous rotation of roll/pitch,
then rotate around resulting body z-axis to align the heading.

This should "fix" the setpoint passed to the attitude stabilization if in HOVER or NAV
at large angles.
Only tested quickly in simulation...
[rotorcraft] v_adapt: limit min/max estimated hover throttle

The adaptive vertical filter estimates the ratio of vertical acceleration over thrust command.
In effect this will now limit the throttle applied in hover between 20% and 75% of max throttle by default.
[fixedwing] additonals for energy ctrl

better handling for engine out and max_acc can be set in airframe
closes #497
[modules] fix to use amsys airspeed for control
[modules] a little airspeed_amsys cleanup
[mcu_periph] replace gpio_output_[high|low] with gpio_[set|clear]

That means using the already existing gpio_set and gpio_clear from libopencm3 for stm32.
And defining these for the lpc.
set paparazzi_version to v5.1_devel
fix to use ins_alt_dot with baro wen USE_BAROMETER is defined
[modules] angle of attack sensor fix and cleanup
[dox] update comment in state inteface
improve paparazzi_version if git tags are not found
[modules] baro_board: only call event handler if there is new data
[modules] fix warning in baro_board
[modules] baro_amsys: fix for DT to match BARO_READ_PERIODIC_PERIOD
[modules] BARO_x_DT from generated BARO_x_PERIODIC_PERIOD
[modules] baro_amsys: comment to match the other baro sensors
Merge pull request #498 from flixr/gpio_setclear

[mcu_periph] replace gpio_output_[high|low] with gpio_[set|clear]