BitmapDataTest - updated to test locked operations
Added missing return data type to some functions
Started work on TS / JS conversion of SingleFileLoader
URLLoader: Fixed bug - disposing should remove reference to URLRequestRequest NOT dispose the URLRequest .
IMGLoader: Fixed bug - disposing should remove reference to URLRequestRequest NOT dispose the URLRequest .
ISingleFileLoader - Interface for JS Loaders ( ImageData from URL Loader cannot be used in same manner as AS3 - so we need to have an Interface to actual loaders)
SingleFileURLLoader - Interface implementation for parsers that require URLLoader
SingleFileImageLoader - Interface implementation for parsers that require ImageLoader