Fixed grooveshark not detecting song status and made buttons work.

Hacked this together after discovering that the addon no longer works.  This uses the deprecating unsafeWindow object everywhere.  Will need to find a new way to interact with Grooveshark when it does get deprecated.  Buffering status has been as well since I can't seem to find the api call for it.  Still working on unloading when page is no longer on grooveshark.