Original commit message from CVS: * gst/mve/gstmvedemux.c: (gst_mve_demux_get_src_query_types), (gst_mve_demux_handle_src_query), (gst_mve_demux_handle_src_event), (gst_mve_add_stream): Support SEEKING query (bad news now delivered properly!); add event function to source pads to make sure seeks aren't propagated upstream, even if they aren't handled.