1)  API issue: parent interface for parent... not exactly right.
	move add_child down to container
2)  event polling vs. carter's callbacks...
	stick with polling
3)  gc's in surface as shared_ptr ?
	yes
4)  specify parent in constructor OR call add_child... not both
	move add_child calls to widget constructors
5)  bool return type for slots OK?  sig_and ok?
	no, combiners/return types on a per signal basis
6)  event hierarchy (multiple types per class ok?)
	fine, ditch quit_event
	add joystick event
7)  empty constructors (state->container->widget)
	need them
8)  font support
	font class (file, size, style, fg, bg, outline)
	cached in bitmap
	singleton map of fonts
9)  Rectangle as a position representation

10) Naming of smart ptr Typedefs

11) Weak pointers in public interfaces

12) Focus model / algorithm
