Make sure not to attempt to store barlines.
Made the clear all button work.
Moved the toolbar to a separate module.
Rewrote the copy/cut/paste/delete code.
Fixes #3.
Cleanup of editing events, fixes #6.
Major rework of update events, splitting them into text and structure
changes.
Fixes #7: Barlines aren't updated during edit
Work on chord events.
Trying a lighter color for the placeholder texts.
Fixed #9 : Update events are triggered during initial rendering