additionals to use amsys sensors to measure airspeed
[math] fix ecef_of_[ned|enu]_i
[modules] remove unused baro_x_updated vars
[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 samara2