MSS - Wrong representation id if StreamIndex has no 'name' attribute
Created by: jeremco
Hi
This PR solves the problem described by @danrossi in issue #1938 (closed), using smooth streaming manifest http://videos.electroteque.org/playready/big_buck_bunny.ism/Manifest
In the case there is no 'Name' attribute in manifest StreamIndex node, representation id is of type : null_0, and in this case one video representation and one audio representation could have the same ID.
Jérémie