Fixed a bug in GeneralApplication that caused prerequisite theorems to n...

...ot include the theorem that spawn the step, hosing proof output.  Fixed a bug in MainProofLevel that caused cycle detection to fail when multiple cycles were encountered.  Added a defensive check to removeConsequent in PerVCProver.  Fixed a bug in ExpandAntecedentBySubstitution that caused equality theorems to become symmetrical and then make meaningless changes.  Fixed an error in MTType that allowed equals() to go into an infinite recursive loop.