reimplement getAnnotationCountsByOntologyTermUri using recursion for
recursive

There seems to be no easy way to get either SPARQL or Sesame to do it
inside of a single query, as the graph URI needs to be bound to a single
graph, and there is no point binding the graph URI in two different
queries, as the subclassof predicates may be randomly distributed across
both the concrete and inferred triples.