List all styli

[danirabbit]

Theoretically supports multiple stylus

MainPage:

• Use a ListBox to hold stylus views so we get automatic placeholder support
• List all stylus devices, not just the first one

StylusView:

• Set device on construct
• Show device name
• Don't use janky coords thing to pack widgets
• Use a dialog instead of a popover for drawing test area so it's harder to accidentally close and can be resized
• Code style