[uart] replace #ifdef USE_UARTx with #if USE_UARTx
[tools] calibrate.py: exit with meaningfull error if optimization fails
[conf] use quad_lisa_mx as quad x-configuration example
use correct word in FP button to circle around a point
[fixedwing] settable LOW_BATTERY_KILL_DELAY

should probably be replaced by electrical.bat_critical instead of re-implementing the delay for the critical check there...
closes #610
[uart] if USE_UARTx instead of defined USE_UARTx
[tools] fix typo in get_id of calibration_utils
[nav] GetPosX and GetPosY in nav.h (FW) are in local coordinates

allows to use the macro with sectors detection

fix #602
[catapult] don't use GetPos macros but state interface directly
[rotorcraft] send motor_mixing.nb_failure in ROTORCRAFT_STATUS
[imu] drotek_10dof_v2: more defaults according to PERIODIC_FREQUENCY
[drotek] add missing endif