* [GRAPH_EXPORT,FIX] Added missing import.
* [RDF_SERIAL,FIX] Fixed wrong predicate arity in public predicates list.
* [RDF_SERIAL,NEW] Added rdf_save2/2 wrapper of rdf_save2/3.
* [XML,SC] Use setup_call_cleanup/3 for file_to_xml/2.
* [XML,EXT] Close the stream after reading from it in file_to_xml/3.
* [XML,FIX] Added missing import.