Fix spelling mistake in docs
Add documentation link to readme.
Add API reference link to README
Move quote in README
Prepare the next development cycle (0.2.0-SNAPSHOT)
Update clojurescript compiler version.
Add human readable exception when pure/return is used without context.

(only for clojure at this time)
Add missing license header on each source file.
Move clojure(script) types extensions to separated namespace.
Identity monad
Transformers proof-of-concept

By decomplecting the monadic value types from the monad's behaviour
having transformers is now possible. The existing API still works, but
there are still a few problems I'd like to address:

 * using monad transformers with mlet syntax;
 * automatic lifting within mlet in a transformer context (should be
   possible with `inner` and `lift`);
 * renaming of `core.lift` to `core.lift-m`;
 * adding back the set, list and lazy seq monads.
.clj -> .cljx
Either monad transformer
Rename monadic lift to lift-m and implement core.lift
Add ns declarations
Reorder continuation monad ns requires
Prepare core.cljx for working with monad transformers and fix tests
Move monad tests to their own file
cats.builtins and docs update
Add changelog