Change LookAndFeel to system's
Remove abc4j library
Add JMusic library with source and jdoc
Rename class Note to MusicBuzzerNote
Integrate Note and Duration with JMusic
Add Listener to update ComboBox when slider changes
Remove unnecessary imports
Merge branch 'jmusic-library' of https://github.com/telis93/MusicBuzzer.git into jmusic-library