gst/avi/gstavidemux.*: Initial streaming support for avidemux (fixes #336465)

gst/avi/gstavidemux.*: Initial streaming support for avidemux (fixes #336465)

Original commit message from CVS:
* gst/avi/gstavidemux.c: (gst_avi_demux_class_init),
(gst_avi_demux_init), (gst_avi_demux_dispose),
(gst_avi_demux_reset), (gst_avi_demux_index_next),
(gst_avi_demux_index_entry_for_time), (gst_avi_demux_src_convert),
(gst_avi_demux_handle_src_query), (gst_avi_demux_handle_src_event),
(gst_avi_demux_peek_chunk_info), (gst_avi_demux_peek_chunk),
(gst_avi_demux_stream_init_push), (gst_avi_demux_stream_init_pull),
(gst_avi_demux_parse_subindex),
(gst_avi_demux_read_subindexes_push),
(gst_avi_demux_read_subindexes_pull), (gst_avi_demux_parse_stream),
(sort), (gst_avi_demux_parse_index), (gst_avi_demux_stream_index),
(gst_avi_demux_sync), (gst_avi_demux_peek_tag),
(gst_avi_demux_massage_index), (gst_avi_demux_stream_header_push),
(gst_avi_demux_stream_header_pull),
(gst_avi_demux_process_next_entry), (gst_avi_demux_stream_data),
(push_tag_lists), (gst_avi_demux_loop), (gst_avi_demux_chain),
(gst_avi_demux_sink_activate), (gst_avi_demux_activate_push),
(gst_avi_demux_change_state):
* gst/avi/gstavidemux.h:
Initial streaming support for avidemux (fixes #336465)