Quite a few changes, mostly revolving around rewriteof and depth module.
The depth was not being calculated correctly, as the rewriteof was not
being correctly applied whenfinding parents. Has been modified such that
findOrCreateNode now applies it immediately, such that it is nearly
impossible to use the rewritten node (except by iterating through all
nodes).
Also added data for CommonConcepts to include URLFn (which is now
unreifiable).
And fixed up some NLP code that was bugging out for non-DAG nodes.