No logging.
Merge branch 'master' into nologging
Merge branch 'master' into nologging
Added functions to ParseTreeNode to enable detection of supertrees (e.g., is_supertree_of returns a boolean).
Really impossible to undo the commit which stopped logging so just manually undoing it.
Merge pull request #93 from salspaugh/nologging

Made important changes in no-logging branch that I infuriatingly can't move elsewhere.