Added owl use.
declare-classes now supports default frames.
New comment into TODO.
All functions in tawny.owl now use explicit ontology.
All functions in reasoner and reasoner_test now use an explicit ontology
Fix to as-subclasses to take a list.
New refine method for AnnotationProperty.
Whitespace cleanups.
New version of ELK.
Default Ontology problem write up.
Many functions now accept nil as an ontology argument. Only those that
will definately use one require this argument or the default ontology to
be set.