Character to add to humtr

[craigsapp]

In polishscores.org/?id=15xx:255 lyrics (modernized characters), there is the character Ӡ which needs to be modernized to Z:

[craigsapp]

Impemented with commit https://github.com/craigsapp/humlib/commit/8035506406c89328ef8860355196570ce856eda2

Note that there are two different characters in the digital scores for old Z being used (they look the same):

Ʒ:Z Ӡ:Z

First one is https://en.wikipedia.org/wiki/Voiced_postalveolar_fricative

Second one is https://en.wikipedia.org/wiki/Abkhazian_Dze

[craigsapp]

Fix online: