gst/elements/gstfilesink.c: Fix for if we pass NULL as property to location.

gst/elements/gstfilesink.c: Fix for if we pass NULL as property to location.

Original commit message from CVS:
2004-01-07  Ronald Bultje  <rbultje@ronald.bitfreak.net>

* gst/elements/gstfilesink.c: (gst_filesink_set_location):
Fix for if we pass NULL as property to location.
* gst/elements/gstpipefilter.c: (gst_pipefilter_init),
(gst_pipefilter_handle_event), (gst_pipefilter_chain):
Fix for instantiate-test (see below).
* gst/gststructure.c: (_gst_structure_parse_value):
Fix compile error on gcc-2.96.
* configure.ac:
* tests/Makefile.am:
* tests/instantiate/Makefile.am:
* tests/instantiate/create.c: (create_all_elements), (main):
Add a test that instantiates all elements. This makes it easy to
track dead code for old API/design (like setting event functions
on sink pads and so on).