* Added MemcacheStorage, sits on top of another storage provider and uses memcached to cache metadata and asset data
* Implemented Robert's suggestion to replace AssetURL with a list of method to URI mappings that contains data=>uri
* Upgraded to latest ExtensionLoader with simplified extension starting
* Simplified SimpleStorage by removing SimpleMetadata and using a dictionary of UUID to filenames
* Moved Metadata into its own file, added serialization and deserialization methods
* Added LICENSES.txt file for third party libraries (not complete yet)