ext/ogg/: Added ogg-in-avi parser element. Fixes #140139.

ext/ogg/: Added ogg-in-avi parser element. Fixes #140139.

Original commit message from CVS:
* ext/ogg/Makefile.am:
* ext/ogg/gstogg.c: (plugin_init):
* ext/ogg/gstoggaviparse.c: (gst_ogg_avi_parse_get_type),
(gst_ogg_avi_parse_base_init), (gst_ogg_avi_parse_class_init),
(gst_ogg_avi_parse_init), (gst_ogg_avi_parse_finalize),
(gst_ogg_avi_parse_setcaps), (gst_ogg_avi_parse_event),
(gst_ogg_avi_parse_push_packet), (gst_ogg_avi_parse_chain),
(gst_ogg_avi_parse_change_state), (gst_ogg_avi_parse_plugin_init):
Added ogg-in-avi parser element. Fixes #140139.
* ext/ogg/gstoggmux.c: (gst_ogg_mux_buffer_from_page):
Fixed a bug in oggdemux debug code.
* gst-libs/gst/riff/riff-media.c: (gst_riff_create_audio_caps),
(gst_riff_create_audio_template_caps):
Recognise Ogg in the AVI extensible wave format.