The SmtEngine now ensures that setLogicInternal() is called even if there is no expli...

The SmtEngine now ensures that setLogicInternal() is called even if there is no explicit setLogic().  This is important for the CVC language, where the parser doesn't ensure that setLogic() is called, and for API uses.  setLogicInternal() should be called in order to properly set up heuristics, even if the logic is just ALL_SUPPORTED.

This means that the CVC language can now take advantage of statistics.

Also added the ability to set the logic from CVC presentation language via (e.g.)
  OPTION "logic" "QF_UFLIA";

Disabled the justification decision heuristic for ALL_SUPPORTED, as it interferes with incrementality.  Kshitij may have a fix (I warned him about this commit).