Add lazy-monad (using clojure delay).

Not finished.
Some tests fails on clojure but not in clojurescript :S 
Pending: transformer. (would be awesome having functions that works with eigher in a lazy way  :P)

Question: fapply should return same type as `av` or `af`? I thing it should be of `av` but currently all implementations uses type of af that is same as of `m`.