docs/random/ds/element-checklist: Notes about gst_caps_to_string()

docs/random/ds/element-checklist: Notes about gst_caps_to_string()

Original commit message from CVS:
* docs/random/ds/element-checklist: Notes about gst_caps_to_string()
* gst/registries/gstxmlregistry.c: (gst_xml_registry_save_caps):
Fix memory leakage of gst_caps_to_string().
Use GST_PTR_FORMAT instead of gst_caps_to_string():
* gst/autoplug/gstsearchfuncs.c: (gst_autoplug_sp):
* gst/autoplug/gstspideridentity.c: (spider_find_suggest),
(gst_spider_identity_sink_loop_type_finding):
* gst/elements/gsttypefind.c: (gst_type_find_element_have_type),
(find_suggest):
* gst/gstpad.c: (gst_pad_try_relink_filtered),
(gst_pad_set_explicit_caps):
* gst/parse/grammar.y: