CVE-2012-0037

Enforce entity loading policy in raptor_libxml_resolveEntity
and raptor_libxml_getEntity by checking for file URIs and network URIs.

Add RAPTOR_OPTION_LOAD_EXTERNAL_ENTITIES / loadExternalEntities for
turning on loading of XML external entity loading, disabled by default.

This affects all the parsers that use SAX2: rdfxml, rss-tag-soup (and
aliases) and rdfa.
static void raptor_rdfa_character_data(void *user_data,
                                       raptor_xml_element* xml_element,
                                       const unsigned char *s, int len)
{
  character_data(user_data, (const char *)s, len);
}

static void raptor_rdfa_character_data(void *user_data,
                                       raptor_xml_element* xml_element,
                                       const unsigned char *s, int len)
{
  character_data(user_data, (const char *)s, len);
}
