Enable / implement Quad pattern resolver

[agazzarini]

1. Note the "false" hardcoded value passed into the resolver method.

var response =  resolver(false).linkedDataFragment(
                                       ofNullable(subject), ofNullable(predicate),
                                       ofNullable(object), ofNullable(graph), ofNullable(pageNumber));

2. Add the "graph" variable in the mapping section.

var templateAndMapping = model.createResource()
                .addProperty(HYDRA_TEMPLATE, template(request))
                .addProperty(HYDRA_VARIABLE_REPRESENTATION, HYDRA_EXPLICIT_REPRESENTATION)
                .addProperty(HYDRA_MAPPING,
                        model.createResource()
                                .addProperty(HYDRA_VARIABLE, SUBJECT_PARAMETER_NAME)
                                .addProperty(HYDRA_PROPERTY, RDF.subject))
                .addProperty(HYDRA_MAPPING,
                        model.createResource()
                                .addProperty(HYDRA_VARIABLE, PREDICATE_PARAMETER_NAME)
                                .addProperty(HYDRA_PROPERTY, RDF.predicate))
                .addProperty(HYDRA_MAPPING,
                        model.createResource()
                                .addProperty(HYDRA_VARIABLE, OBJECT_PARAMETER_NAME)
                                .addProperty(HYDRA_PROPERTY, RDF.object));

3. Add the "graph" parameter in the request template