0.13.0.0

• Support for unique parametrized effects.
  • Each effect can provide an extra constrain on the monad in which it executes
  • One of the applications is a class that provides an extra functional dependency on some of the effects parameters
• State effect now has a functional dependency on the parameter meaning you can only have one state effect in a computation, but the inferrence is much better
• Module for working with newtypes of effects
  • Allows you to tag a certain effect with a new name so multiples of the same effect can be used without interaction
  • This lets you recover the ability to use multiple state effects in the same computation
• Yield effect also gets a functional dependency
• Async effect gets a parameter with a functional dependency enabling different implementations to use different thread representations
• Removed Parallel module. Pretty much covered by Async
• Ability to cancel thread and check if they're done with Async
• Better errors when failing to derive an Effect instance
• Better docs