The spec for loading a media element is quite huge. This implements just
enough to parse the attribute, fetch the corresponding media object, and
decode the media object (if it is a video). While doing so, this also
implements most network state tracking and firing DOM events that may be
observed via JavaScript.
The intent is to use these to autogenerate prototype declarations for
Window and WorkerGlobalScope classes.
And the spec links are just nice to have :^)
