Todo / Known bugs:
- CTRL + O : can't override browser shorcut
- create file => save as test.json + save as test.png => close LayerPaint, close browser => open browser, open LayerPaint => drag-n-drop test.json from explorer to LayerPaint => modify something => [Save] works without Browse popup, good => [Save as PNG] requires to Browse => how to solve ?
- zoom : should be improved, not vector yet