Re-factored the Turtle serialiser to use the internal array index, instead of using the EasyRdf_Graph API.
Re-factored the Turtle serialiser to use the internal array index, instead of using the EasyRdf_Graph API.

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