[Swoop] new TurtleRenderer

[Taowei David Wang]

The TurtleFormatEntityRenderer is already getting hard to maintain because
of dodgy design.  I have create a new Turtle renderer
TurtleEntityRenderer, which follows the design of the
AbstractSyntaxRenderer.  Much cleaner code.

For now, both Turtle renderers exist.  The old version will be removed
once the new one is completed.  For now users (from SVN) will see both
"Turtle" and "Turtle (new)" renderer tabs.  The new renderer will render
the koala ontology nearlyly correctly.  But it does not yet render
Properties yet.  For more details, see the change log.

Dave