This module allows for rdf_load('http://...').
It exploits the library library(http/http_open.pl). The
format of the URL is determined from the mime-type returned by the
server if this is one of
text/rdf+xml, application/x-turtle or
application/turtle. As RDF mime-types are not yet widely
supported, the plugin uses the extension of the URL if the claimed
mime-type is not one of the above. In addition, it recognises
text/html and application/xhtml+xml, scanning
the XML content for embedded RDF.