Hooks for overriding default cue styles make this library no longer useable by client-side code

[Gary Katsevman]

The change made in 352982f added a bunch of references to Services which is only available internally in firefox code. Makes it so that we can no longer use this library in client-side code.

[Calvin Walton]

I don't think this is actually the case; all of the calls that reference the Services object in that commit are behind a check with if(typeof Services !== "undefined").

If you have an object named Services in your own code, I guess this might conflict, but otherwise it should still work fine in client-side code.