Add support for resource URIs (<http://example.org/class>) to Graph->isA resp. Resource->isA methods
Add support for resource URIs (<http://example.org/class>) to Graph->isA resp. Resource->isA methods

bsampaio/PHP-SemanticWeb-20142,bsampaio/PHP-SemanticWeb-20142,bsampaio/PHP-SemanticWeb-20142