[Property] Add MediaItem2 resource properties to Container. Fix UpdateCount.

Add URLs, Size, DLNAProfile & Mime/Types resources

We can now filter out URLs for Container, using SetProtocolInfo API

Second part for bug https://github.com/01org/dleyna-server/issues/5

In addition this commit fixes the UpdateCount property that wasn't
managed in the Get_Prop() method.

Signed-off-by: Ludovic Ferrandis <ludovic.ferrandis@intel.com>
[Documentation] Explain Container reources in more detail.

Added some extra text to explain in more detail what container
resources are.

Signed-off-by: Mark Ryan <mark.d.ryan@intel.com>