add low pass filter to meas airspeed driver including logging of filtered value
Merge remote-tracking branch 'upstream/master' into diff_press_filter

Conflicts:
	src/modules/sdlog2/sdlog2.c
fix logging of filtered diff pressure signal
sensors: use filtered diff pressure to calculate airspeed
Merge remote-tracking branch 'upstream/master' into diff_press_filter

Conflicts:
	src/drivers/meas_airspeed/meas_airspeed.cpp
Merge branch 'diff_press_filter' into diff_press_filter_use

Conflicts:
	src/modules/sensors/sensors.cpp
Added youcompleteme config.
Merged airspeed filtering from Thomas Gubler
Merged airspeed sensor use
mavlink: Hotfixed HIL battery status publication
Merge pull request #768 from jgoppert/youcompleteme

Added youcompleteme config.
Merge branch 'master' of github.com:PX4/Firmware into hil_range_fix
mavlink / HIL: Split handling of actuator feedback between fixed wing and multicopters