Stream
------
stream( url ): Instantiate a stream object for specific url.
+memory_stream( string ): Instantiate a stream object containing a specific string.
+ Those two functions return the stream object upon success and nil if an
+ error occured, in that case, the second return value will be an error message.
s = vlc.stream( "http://www.videolan.org/" )
s:read( 128 ) -- read up to 128 characters. Return 0 if no more data is available (FIXME?).