Refactor lattice templates to support monotonicity checking

[jhellerstein]

We want to "whitelist" monotonicity, and carry the "taint" of non-monotonicity through the type system.

Possible approaches: use C++ traits

[jhellerstein]

• Probably need to have monotone lattice functions inherit from something that assigns the is_monotone trait.
• Would also be nice to organize the code so that we segregate or flag functions as is_morphism, is_monotone or "other"...