YUI Loader
    Processes dependencies and dynamically loads script and css for YUI and external modules.

3.0.0
  * Extracted from the YUI seed.  Now fetched dynamically if
    there are missing dependencies if not included.
  * Reads metadata from on-page modules registered via Y.add if the module is not already known.
  * Many new modules, many modules reorganized, dependency information has been tuned.