Added example showcasing settings panels
Unify Settings menu and content widgets

Replaced with single interface widget, for better general configuration.
Fixed settings example to fit with recent changes
Update documentation to reflect interface change
Fixing documentation to reflect changes
Remove debug code from SettingsWithTabbedPanel
Consolidated settings layout doc in app.py
fix scrolling bug.
If running on a desktop where the default is now to have a permenant scroll bar with scrolling only on the bar, the scroll bar needs to be thicker than 2dp.
Mouse scrolling doesnt need the effects. So dont use it. Fixes a mouse scrolling bug.
Fix scroll view size when no scrolling is needed.
Fix last commit.
Exposes effective width/height/y to user.
Fix filechooser to use new view_width so file size is not hidden by scrollbar.
Implement dragging behavior.
Adds drag behavior to popup.
Dispatch touch to children when outside dragging box.
Don't skip if touch collided.
Don't add drag behavior to popup.
Add example for making popup draggable.