python/tests/test_fft.py: update, indent
python/tests/test_fvec.py: clarify
demos/demo_onset.py: simplify imports
python/demos: add demo_pitch.py and demo_waveform_plot.py
demos/demo_waveform_plot.py: improve
demos/demo_sink_create_woodblock.py: table lookup to improve synthesis
lib/generator.py: move add_generated_objects and generated_types_ready to .c file
tests/test_cvec.py: add missing header