Merge branch 'RTSD-264' into 'master'

...ications/lofar2/model/pfb_bunton_annotated/Gen_filter12.m

...ns/lofar2/model/pfb_bunton_annotated/polyphase_analysis.m

...lofar2/model/pfb_bunton_annotated/polyphase_synthesis_b.m

applications/lofar2/model/pfb_bunton_annotated/reconstruct.m

applications/lofar2/model/pfb_os/dsp_study_erko.txt

applications/lofar2/model/pfb_os/multirate_mixer.ipynb

applications/lofar2/model/pfb_os/pfb_reconstruction.ipynb

applications/lofar2/model/rtdsp/__init__.py

applications/lofar2/model/rtdsp/dftfilterbank.py

applications/lofar2/model/rtdsp/multirate.py

applications/lofar2/model/rtdsp/singlechannel.py

applications/lofar2/model/rtdsp/utilities.py