Data for ConstrainedTerm and SymbolicUnifier
Merge remote-tracking branch 'origin/unified-builtins2' into segregate-data-in-rewriting
Data separated for ConstrainedTerm, SymbolicConstraint, and SymbolicUnifier
make lookups and constraint `final`
Merge remote-tracking branch 'origin/unified-builtins2' into segregate-data-in-rewriting
Merge pull request #622 from kframework/segregate-data-in-rewriting

I have a green light from Andrei.