Don't apply initialization parameters until after createdCallback() returns.
This means that buildRendering() runs before any user the user defined parameters
are available.

This change is necessary to be forward compatible with browsers that implement
document.register() natively, because then programmatic creation (w/out
the syntactic sugar) will be:

var node = document.createElement("dui-slider");
node.max = 10;

Also remove runAfterRender().
get Button working w/new lifecycle