[imu] add LISA_S_UPSIDE_DOWN hack
[rotorcraft] FAILSAFE mode: neutral attitude, downward vel even if FAILSAFE_GROUND_DETECT not used
[gcs] on flight plan save: correct dtd for subdirs

not nice, but works...
[rotorcraft] failsafe and ground_detect

- always reset ground detection
- KILL if in FAILSAFE and not in_flight anymore
[math] dox cleanup
[airframe] Lisa-S enable possibility for auto-takeoff
[SuperBifRf] Smaller Message for vertical loop tuning
[airframes] TUDelft IMAV Entries
[Module] Flight time left
[board] Fireswarm
[Ocaml] Block and Setting numbers
[ArDrone] Navdata decoder update (incl sonar)
[fix] cleaning

- remove compilation warning in gen_airframe
- better (?) ocaml relative path substitution for editFP
[fix] previousUltrasonicHeight in navdata is static now
[dox] fix some more MSL vs. ellpsiod alt comments
[ArDrone] Fix breaking autoconfig
[math] geodetic_int: add extra ecef <-> enu/ned position functions

- ecef_of_enu_point_i has coordinates in cm
- ecef_of_enu_pos_i has ned in meter with INT32_POS_FRAC and ecef with cm
[state] fix local ned/enu to ecef conversion

by using new ecef_of_enu_pos_i functions which have enu in meter with INT32_POS_FRAC and ecef with cm
instead of everything in cm
Initial support for Lisa/MX (the Cortex-M4 version of Lisa/M)