[ahrs] remove HIGH_ACCEL_FLAG

It is way too dangerous and not needed anymore with the latest imu
sensor. Keeping it for arduimu just in case
[tools] Added process_exif script

closes #483
[uart] add data bits, stop bit and parity config function for uart

only implemented on stm32
[radio] add initial support for Futaba SBUS protocol
[sbus] sbus driver working
[sbus] code cleaning and comments
[sbus] use uart functions instead of macros
[sbus] use gpio helper functions instead of abusing LED
[mcu_periph] sane defines for UART bits defines
[sbus] fix polarity
[fix][fixedwing] init state interface _before_ sensors and ins

This had the very very nasty effect that the local coordinate system was not initialized
if NavSetGroundReferenceHere() was not called from the fliht plan,
(e.g. because not waitinf for GeoInit to finish).
Merge pull request #471 from gautierhattenberger/master

Remove HIGH_ACCEL_FLAG
Merge pull request #485 from paparazzi/sbus

Sbus radio control driver
[fix] fix warning, missing include, and more configuration
[conf] add krooz_quad example conf
[conf] replace stabilization euler by int_euler in examples
[airframe] add new airframe for Quark plane
[dox] nicer doxygen formatting for pprz_transport
[dfu] Improved progress bar during programming
[boards] krooz_sd: fix I2C1_GPIO_SDA pin