Merge pull request #341 from podhrmic/master

Baro MS5611 interface for Lisa M/Lia - SPI, I2C, Aspirin I2C
[conf] don't try to sort/remove duplicates in aspirin_v2.1 makefile, this throws out valid entries somehow as well...
[stm32] removed obsolete attempts of the i2c driver
[lisa_m] fix test_baro, remove trailing whitespaces and fix indentation in baro_board*
[doc] correct description for baro_amsys module
[boards/lisa] fix test baro for lisa_l as well..
[imu] minor config name change for aspirin
Merge branch 'master' into peripherals_imu_refactor
[dox] fix some doxygen file blocks for fixedwing firmware
[actuators] throw informative error if still attempting to use MIN|MAX_MOTOR with new motor_mixing
[subsystems][imu] cleaned up imu_ppzuav driver no modules for imu_ppzuav and imu_aspirin_i2c anymore
[imu] signs for mag in aspirin imu should be correct again, still needs checking though
[conf] remove duplicates after setting all flags and sources
Revert "[conf] remove duplicates after setting all flags and sources"
Doesn't work as intended (yet).
The sorting e.g. splits up `pkg-config glib-2.0 --cflags` into
--cflags` glib-2.0 `pkg-config
so it doesn't work anymore...
One way could be to make sure to resolve these first before sorting.

This reverts commit 70168207abc7f5c2b6a0fc766e03e8bf2b633009.
[conf] use a common spi.makefile to include the sources and general SPI flags
[build_system] removing duplicates for all airborne targets should work now.
pkg-config and the like need to be expanded via $(shell instead of using backquotes.
No spaces between -I and dir for generated module includes"
[dox] extract only documented files, strip code comments again...
[dox] okok... extract all again, but we should really just document the ones we want and only extract those
removed stray endif
[state_interface] fix float hmsl, thx Freek