improve, fix and extend plugin dosumentation

not sure about the changes in mstyle though
make partName writable from plugins

and add longName and shortName to the plugin framwork
fix previous change

hopefully. I really should get myself a proper build enviornment...
reverting changes to the files in mstyle
some Gonville fixes
install Gonville.otf on mac
Merge branch 'gonville+' of github.com:Jojo-Schmitz/MuseScore
Merge pull request #637 from Jojo-Schmitz/orig_txt

fix #23366: capitalization
Merge pull request #635 from Jojo-Schmitz/plugins

Plugin framework improvments
small build fix