OSMF SVN

Fix FM-60: MediaPlayer.load swallows exceptions. The fix is to convert exceptions into MediaErrorEvents with the details of the failure. This approach is preferred over throwing an exception, because this is an error which doesn't strictly qualify as a programming error (e.g. the exception may be due to passing an resource to a MediaElement that doesn't handle it, and the MediaPlayer client may just be acting as a pass-through). Updated unit tests and ExamplePlayer with another failure sample.