Measure the battery voltage of Aero RTF kit will be done by FPGA
and read by AeroFC using I2C bus.
The protocol is a little bit odd, it have different I2C slave
address for each "register", in future the FPGA RTL will
have a protocol more similar to other I2C sensors.
Also Aero RTF don't have a ADC line to measure current consumption.
* Low impact changes from path_cleanup branch.
This is a step towards minimizing the diff with path_cleanup branch.
* Update ecl.
* Revert matrix update.
* Revert ecl and matrix.
* Update sitl gazebo.
* Revert sitl_gazebo and matrix changes.
Now the mixer is a C++ library that can be fairly easily bolted into an output driver to provide mixing services.
Teach the FMU driver how to use it as an example. More testing is still required.