Infinite loop protection fault on Whittaker sub-biome

http://mm2.idea.informer.com/proj/MM2?ia=136753#comment_form

Requesting re-entrant graphs is not guarded against and bombs the editor.

Steps to reproduce: make new Graph called "CallWhittaker" Call up a Whittaker graph inside our new "CallWhittaker" Graph add as one Whittaker outputs "CallWhittaker"...