Support asynchronous ControlManager and Container

[markusjohnsson]

To support SystemJS we need to have asynchronous Control instantiation in ControlManager, because even though modules are in-memory after System.register('module'), there is no way to get a (fully resolved) module out of SystemJS except through a Promise.

We need an asynchronous overload for Container.resolve that can be used by ControlManager to create instances of controls.