gst/subparse/: Add support for TMPlayer-type subtitles (#362845).

gst/subparse/: Add support for TMPlayer-type subtitles (#362845).

Original commit message from CVS:
* gst/subparse/Makefile.am:
* gst/subparse/gstsubparse.c:
(gst_sub_parse_data_format_autodetect),
(gst_sub_parse_format_autodetect), (handle_buffer),
(gst_sub_parse_chain), (gst_subparse_type_find), (plugin_init):
* gst/subparse/gstsubparse.h:
* gst/subparse/tmplayerparse.c: (tmplayer_parse_line),
(parse_tmplayer):
* gst/subparse/tmplayerparse.h:
Add support for TMPlayer-type subtitles (#362845).
* tests/check/elements/subparse.c: (test_tmplayer_do_test),
(GST_START_TEST), (subparse_suite):
Add some basic unit tests for the above.