Mensural Sign for Cut-Circle over 3

[benory]

Can we implement the mensural sign "Cut-Circle over 3"?

The issue was previously raised here: rism-digital/verovio#3525

[craigsapp]

Also added issue humdrum-tools/verovio-humdrum-viewer#873 to keep it in mind.

[craigsapp]

You can remind @lpugin about issue rism-digital/verovio#3525 (which this message is designed to do 😜 ).

[craigsapp]

Should now be possible:

**kern
*clefC3
*M2/1
*met(O|/3)
=
0.c
=
*-

(in about 20 minutes after verovio is compiled for online use in VHV.)

[benory]

This is absolutely fantastic! Thanks @craigsapp for so quickly implementing this. I've updated all of my scores accordingly.