Important:
- Resize components with keyboard

- Show realtime updated properties when dragging components
- Show properties of main window (especially width/height when resizing)

- Add a confirmation box when clicking New if unsaved changes

Nice:
- Add support for hosting guieditor within application
  - Allow registering custom components so they show up correctly rendered in the editor
  - Allow using custom gui theme for rendering layout

- Drag'n'drop components from toolbar onto layout

- Snaplines are confusing when there are many components
- Snaplines lacking baseline support
