Improving Noteworthy converter support

[nvuaille]

Motivation
Improving the Noteworthy Converter, for more interoperability

Feature summary
Centered on version 1.75, binary and text format.

Proposed implementation
Improve supported NWC objects parsing in https://github.com/cuthbertLab/music21/blob/master/music21/noteworthy/binaryTranslate.py
By design, this also require some improvements in https://github.com/cuthbertLab/music21/blob/master/music21/noteworthy/translate.py (binary translate pass a text stream to
the translate module)

See my current branch here. I think I have most of the features I want, I still need update/fix current tests and add more =)

Intent

• I plan on implementing this myself.

Is it something music21 would like to have ? Is there some recommendation about this kind of feature ?

In any case, thanks for all the work you did on this great tool !

[mscuthbert]

most welcome contribution if you have it! I'll need to fire up my PC to get some more files.