[dox] fix typos: rates are in rad/s
[lpc21][imu] aspirin_i2c defaults to i2c0, configurable via ASPIRIN_I2C_DEV
[makefile][imu] configurable ASPIRIN_I2C_DEV
[conf] remove unused MAG_[XY|XZ|YZ]_SENS defines
[ext] update luftboot submodule

PREFIX now needs the trailing dash, so /foo/bar/arm-none-eabi-
[ext] PREFIX without trailing dash again, like in libopencm3
[imu] aspirin: print SPI/I2C devices
[config] consistent foo_I2C_DEV and PRINT_CONFIG
[lpc21][i2c] clear naming for i2c channel
[mcu] add missing include for INFO macro
[lpc21][i2c] trying to fix disabling/re-enabling of i2c interrupts
[lpc][IRQ] disable all interupts when i2c or spi submit

it is not what we want, but the result is a much more stable code,
might be due to asynchronous behavior of VIC/core interaction

needs deeper investigation
[sonar] and event hook to use the sonar with the ins
[sonar] split sonar modules with and without ins binding
[doc][modules] minor update to sonar doc
[spi] remove warning
[dfu] print exception
[supervision] allow launching of external tools with absolute path
[rotorcraft] use horizontal guidance ref by default

Also use the horizontal guidance reference for HOVER mode.
Using the reference can be temporarly disabled via settings.
The reference is then still computed to stay consistent, but not used.
[nps] don't bypass ahrs by default

By default use the result of the normal ahrs estimation,
if you want to bypass that and use the attitude from NPS define NPS_BYPASS_AHRS to TRUE.