[math] buf fix on geodetic function
[rotorcraft] add MODE_STARTUP to make flying without RC possible

Based on Freek van Tienen's commit, thx.
closes #467 for now
[lpc21] print error if trying to use SPI0 with HAL
Merge branch 'master' of git://github.com/paparazzi/paparazzi into highwind
Added outline for betty paparazzi airframe file
Added IMU calibration files
Added a set_servo function for highwind ground station control operations