#49 Changed the ResourcesCollectionReaderException to extends the ContentLoadException.
#49 New test for ResourcesCollectionReader to check if the same instance was returned after load the same content for the second time.
Fixed the namespace of the HideAnimationTest.
#49 Moved all classes related to MockResource to the file MockResource.cs, it still a little ugly, but better.
#49 Old ResourcesLoader and related classes deleted.
#49 Old XMLs deleted.