Added some combinators in Relation.Unary

Patch by Stevan Andjelkovic
Added pointwise isomorphism

Patch by Stevan Andjelkovic
Add >=> and <=< to the monad module.

Patch by Stevan Andjelkovic
Add module containing predicate transformers.

Patch by Stevan Andjelkovic
Add functors on predicates.

Patch by Stevan Andjelkovic
Add applicative functors on predicates.

Patch by Stevan Andjelkovic
Add monads on predicates.

Patch by Stevan Andjelkovic
Add Data.Container.Indexed.FreeMonad

Patch by Stevan Andjelkovic
Add indexed containers.

Patch by Stevan Andjelkovic
Add core module for indexed containers.

Patch by Stevan Andjelkovic
Add indexed W-types

Patch by Stevan Andjelkovic
Add indexed M-types

Patch by Stevan Andjelkovic
Add indexed container combinators.

Patch by Stevan Andjelkovic
Resolved a couple of unsolved metas