gst/elements/gstcapsfilter.c: Free existing caps if the capsfilter changes. Add a...

gst/elements/gstcapsfilter.c: Free existing caps if the capsfilter changes. Add a FIXME about setting those caps on t...

Original commit message from CVS:
* gst/elements/gstcapsfilter.c: (gst_capsfilter_set_property):
Free existing caps if the capsfilter changes. Add a FIXME about
setting those caps on the pads.

* gst/gstutils.c: (gst_element_get_compatible_pad), (ghost_up):
Before adding a ghost pad to a parent bin, check that there isn't
already one for the element on the bin. Prevents infinite recursion
when using decodebin in parse pipelines. Andy says he'll rewrite the
way this works anyway, so ignore the hack.