Making one of the Image Rep testers ARC.
Use NSURLs instead of strings to get the plug-in location.
Re-work how the current render state his handled. It now gets the latest object in the states array instead of being a weak pointer to an item in the states array.
We now have two simple methods for pushing and popping what's on the state array.
Merge branch 'master' into XCode4
Porting code from master to ARC.