Refactoring ReactAggregate to ReactCommuteAggregate.

Cleaning some things.
Organizing container aggregation.
Refactoring aggregates to catamorphs.

Better organized various catamorphs, introduced higher catamorphs.
Comments for fixes.
Refactor to use abelians.
Refactoring the Arrayable typeclass.
Wip on s.
Implementing CataMonoid.