Cant add components without using Screen

[ianharrigan]

When trying to add components by using the .element property and appending them to an existing <div/> the components are never considered "ready" and therefore never resize, or show correctly.

Expected Behavior

Should be able to add a UI anywhere in the DOM tree and it all work as expected.

Test app / minimal test case

class Main {
	static public function main() {
		haxe.ui.Toolkit.init();

		var main = new VBox();

		var button1 = new Button();
		button1.text = "Button 1";
		main.addComponent(button1);

		var button2 = new Button();
		button2.text = "Button 2";
		main.addComponent(button2);

		js.Browser.document.getElementById("content").appendChild(main.element);
	}
}