Loader: Don't lazily init the contentLoaderInfo field

We use it almost immediately after we create it, so this makes
no sense.
extension: Rename some loader variables

Make naming consistent between components.
extension: Use the "flashvars" attribute to grab params from

Embed parameters are not passed to the movie.
Add support for passing movie params

In the case of the inspector, we simply use the entire query string
of the page if there's an "rfile" and pass it directly to the SWF.

In the case of the viewer, we parse the <embed>/<object> parameters.
We eventually may need to parse the query string after the src URL.
Merge remote-tracking branch 'mozilla/master' into fix-params
Implements _getArgs()
Adds params example