Model no longer adds subterms of quantifiers to equality engine, this fixed bug 492...

Model no longer adds subterms of quantifiers to equality engine, this fixed bug 492 and resolves previous issue for bug 486.\n Multiple improvements for E-matching: do not choose multi-triggers if single triggers exist, only create multi-triggers that contain all variables, consider multiple terms per equivalence class but only add one instantiation per round per (trigger,term) pair.\nImprovements for strong solver: make use of sort inference information when choosing splits, check for cliques eagerly when disequalities are asserted.