Rename utility.event to service.event

I hope to eventually add more "service" modules, like a timing service
and such. These all are essentially global objects that are hooked to
and it's helpful to classify them separately.
Rework container
Remove utility.functor

This isn't really useful as of now, and it takes very little code to
implement.
Give ui.element a default constructor
Fix a couple issues with oop::mix
Add a frame class

I initially removed this class with the addition of the OOP mix method,
but because it requires a little bit more glue code than just pure
method mixing, I reimplemented it.
Update the 'demo' and todo