Fix #23059: Accented notes in guitar pro files now displayed.
Added support for heavily accented notes in the GP5 format.
Fix #23055: Support for tremolos in GP4 and GP5 file formats.
Trills in GP4 and GP5 files are now displayed.
Merge pull request #762 from jpirie/master

Support for Accents, Hard Accents, Trills and Tremolos in guitar pro files.