both outputStylesheet and outputScript should be able to take a URL instead of a
resource target - there are times when you want to serve things from someone
else's machine, such as Yahoo or Google.
One use case for this change: You are writing a composite component, which uses
Google's service to load CSS (such as when you use the YUI components). This
means that you currently must either require users to put a <link> tag in the
header, which is clearly undesirable, or that you need to use only local files,
which can in many cases offer worse performance.