objects and interfaces:

Name: GUPnPMediaServer
description: The main object that talks to the control-points.

Name: GUPnPMediaProvider
description: Interface that all Media provider/backend objects must implement.

Name: GUPnPMediaDb
description: Object that:
        - imlements GUPnPMediaProvider
        - manages plugins that provides GUPnPMediaProvider

Name: GUPnPMediaTracker
description: tracker-based GUPnPMediaProvider implementation.
             http://www.tracker-project.org

Name: GUPnPMetadataExtractor
description: Helper object providing metadata extraction facility.