NEW: module for caching RDF using SPARQL.
The intent is to be able to query ANY resource in the LOD cloud and have ALL its propositions cached locally.
We currently take care of:
  - blank nodes
  - literals
  - HTML files
  - image files
  - SPARQL end points
  - remote RDF descriptions
  - symmetric links (e.g. owl:sameAs)
FIX: Added newline after define statement.
FIX: Added determinism for limit//1.
No sure whether this module is needed anymore...
EXT: Simplified serialization recognition again.
EXT: Use default serialization type: turtle.
NEW: rdf_store_table/1 for storing quadruples directly, i.e. not via the Semweb rdf/4 predicate.
This is useful when triples come from SPARQL queries.
Changed timeout seconds.
FIX: translation from directory to its subdirectories was incorrect for trailing slashes, e.g. `/a/b/` -> `[a,b]`.
EXT: Added link to external resource.
BUG: Unicode is not generated correctly in Web pages.
NEW: graph closure predicate that returns propositions, e.g. triples.
Can be used for graphs with labeled edges.
NEW: url_to_graph_name/2.
FIX: url_to_file_name/2 would not work for non-file paths in URLs. We now use `dummy`.