Initial commit of simple logger based on Georgis idea.
Baud rate increased to 3Mbaud, single channel plotter works.
Restructured Monitor
Very slow FIR filter. Fixed-point scaling is not done in the right way.
Fix ADC pullups
FIR-Filter: Created unit tests for FIR filter implementation.

Right now only a "delay line" filter test with handcoded values
is available.
TODO: Add coefficients, taps and results for filters calculated
with octave or scipy etc.
FIR-Filter: rudimentary construct added. TODO: implement filter
FIR: implemented filtering function with loop unroling.

Some further tests and optimizations are needed though.
Merge branch 'develop' into feature/fast_logger
FIR: New buffering scheme. Added debug functions.

The FIR filter now implements a buffering scheme that avoids
shifting the tap buffer every time a new value is appended.
The filter now only needs to shift every BLOCK_SIZE+1 times.
The tradeoff is that it uses BLOCK_SIZE additional memory.

DEBUG: Some debugging defines have been added in fir_impl.hpp
They allow to prinf memory when running unit tests on a PC.
Right now this is implemented by checking whether DEBUG is defined.
This should be improved to automatically detect unit test builds.
FIR: Added ScaleFactor to enable fixed point math.
FIR: Replaced DEBUG define with FIR_DEBUG to prevent errors.
Merge branch 'develop' into feature/fast_logger
FIR: Scale Factor now used to scale down output
Merge branch 'develop' into feature/fast_logger
Merge branch 'feature/fast_logger' into develop