Lots of additions that are needed in order to apply RDF(S) and (later) OWL entailment in a stringent way.

* [ASSOC_MULTI,NEW] New module for association lists whose values are ordered sets. This allows multiple values to be stored under the same key without trading in too much temporal efficiency.
* [ATOM_EXT,EXT] Extended strip/3, strip_begin/3 and strip_end/3 to also take single character input on the first, and character lists inputs on the second and third argument.
* [FILE_EXT,EXT] Extended file_name/4 for building file names out of ingredients.
* [OWL_ENTAILMENT,NEW] New module collating part of the RDF, RDFS, and OWL entailment regimes. Most of this is drawn from the SWI-Prolog semweb library v3 and ClioPatria. The idea is to unify and extend the code in conformance to W3C standards and test cases.
* [RDF_GRAPH,NEW] Added rdf_graph_equivalence/2, based on the W3C RDF-CONCEPTS standard.
* [RDF_SERIAL,NEW] Added N-Triples support for rdf_load2.
* [RDF_SERIAL,FIX] Fixed rdf_load2/3 for instantiation (+,-,+), this now picks the serialization format based on the file's extension.
* [SEMWEB_TESTS,NEW] New module that will automate the RDF and RDFS tests.
** Added test files for RDF and RDFS. The idea is to automatically run these tests from within SWI-Prolog.