check/: Add tests for fdsrc seekability

check/: Add tests for fdsrc seekability

Original commit message from CVS:
* check/Makefile.am:
* check/elements/fdsrc.c: (event_func), (setup_fdsrc),
(cleanup_fdsrc), (GST_START_TEST), (fdsrc_suite), (main):
Add tests for fdsrc seekability

* gst/elements/gstfdsrc.c: (gst_fdsrc_class_init),
(gst_fdsrc_init), (gst_fdsrc_update_fd), (gst_fdsrc_start),
(gst_fdsrc_set_property), (gst_fdsrc_is_seekable),
(gst_fdsrc_get_size), (gst_fdsrc_uri_set_uri):
* gst/elements/gstfdsrc.h:
fdsrc should not be a 'live' source.
Implement seeking on seekable fd's.

* gst/gstquery.c: (gst_query_new_seeking),
(gst_query_parse_seeking):
* gst/gstquery.h:
Implement SEEKING query functions:
*_new_seeking and *_parse_seeking