NoteBlockLib 2.1.0

This version contains several small API changes. Check the README for updated code examples and API usage

Changelog

• Added SongUtil#getNoteCount method
• Added ISongPlayerCallback#playNotes method
• Improved custom instrument handling
• Added NoteConsumer interface and Added FullNoteConsumer interface
• Account for NBS pitch when modifying the note key
• Renamed ISongPlayerCallback to SongPlayerCallback