[ardrone2] Fix AHRS propagate frequency
[ins] INS_PROPAGATE_FREQUENCY defaults to AHRS_PROPAGATE_FREQUENCY if defined
[conf] cleanup INS_ and AHRS_PROPAGATE_FREQUENCY
[rotorcraft] guidance_h_ref: dynacmically adjustable max_speed

- set_max_speed via settings

closes #664
[gps] Add a new GPS based on the datalink
[fms_network] Added multicast support
[ground_segment] Added NatNet to ivy service
[ahrs] Made it possible to set the course deviation of the GPS
[ins] Made it possible to use GPS altitude
[ardrone] Updated gains for inside
[modules] Added a module for following based on received remote GPS