[stm32][spi] select slave after configuring clock/phase, etc of peripheral
Also:
- replace tx_length_case by simpler use_dummy_tx_buf
- minor comment cleanup while here...
[imu] correct mag axes for aspirin_v1.5. RECALIBRATE!!!
[rotorcraft] separate KILL_ON_GROUND_DETECT with higher default threshold
- if KILL_ON_GROUND_DETECT is TRUE, enable killing of motors on ground detection
  used in default land block, add to your airframe file:
  <define name="KILL_ON_GROUND_DETECT" value="TRUE"/>
- THRESHOLD_GROUND_DETECT is now in m/s^2 and defaults to 25 m/s^2
[sw/ext] update libopencm3 to get missing systick_get_reload declaration
[stm32] fix sys_time_usleep, sorry about that...
[tests] test prog for sys_time_usleep
[conf] change warnings about obsolete subsystems to errors
[conf] update mag calib and imu orientation in quadrotor example
[sys_time] no more macros, clenup
should also result in performane improvements since ticks, etc.
are calculated at startup and usec conversions are only fixedpoint now
[sys_time] I hate integer arithmetic with it's overflows...
maybe we should do all the conversions in 64bit and convert back to 32?
[lpc21] fix compilation of servos
We should really use less macros...
[gen] Raise error when unit conversion should have been performed but failed silently (e.g. when adding a space after a float)
[spi] add missing arch indep spi3 init functions
[mcu] initialize spi3 if USE_SPI3
[build system] delete the paparazzi ocaml executable in ~/paparazzi on make clean to ensure any PATH changes for ocaml and ocamlrun are caught after a make clean; make
[radio] Two identical files.
[makefile] Cleanup
[new] XBee auto-baudrate in api mode
removed obsolete IMU_ACC_DRDY_x and libstm based adxl345 test code
[uart] enum UartBaud, remove unused uart_periph_set_baudrate