gst/gststructure.*: Add API for setting values into structures without performing a quark lookup, if the appropriate ...

Original commit message from CVS:
* gst/gststructure.c: (gst_structure_id_set),
(gst_structure_id_set_valist):
* gst/gststructure.h:
Add API for setting values into structures without performing
a quark lookup, if the appropriate quark is already known.
API: gst_structure_id_set
API: gst_structure_id_set_valist
* gst/parse/grammar.y:
* gst/parse/parse.l:
Remove some dead code shown by the coverage information.
Don't throw a critical g_warning when encountering a syntax error,
just warn and let the normal error path handle it.
* plugins/elements/gstelements.c:
Bump the rank of filesink up to PRIMARY so that it is preferred over
gnomevfssink for file:// sink uri's
* tests/check/pipelines/parse-launch.c: (expected_fail_pipe),
(GST_START_TEST), (run_delayed_test),
(gst_parse_test_element_base_init),
(gst_parse_test_element_class_init), (gst_parse_test_element_init),
(gst_parse_test_element_change_state),
(gst_register_parse_element), (parse_suite):
Beef up the tests for parse syntax to check that more error cases
fail as they are supposed to. Increases the test coverage a bit.