Merge pull request #2 from mausch/master

Fix Choice bind
+ Nuget spec file.
+ instances for (,)
+ Library short description.
+ AssemblyInfo.fs
+ Comonads
+ StateT.fs (was missing).
+ Haskell Samples.
+ MonadError
Files reorganized. Sample file reorganized.
Choice Functor fixed.
nuspec completed, version increased.
Removed Either from MonadError.
Tuple overload for catchError left as dummy overload to help Type Inference.
+ ErrorT
+ ErrorT.fs (was missing),
Functor: Fmap changed for Map.
Modules reorganized.
Version 1.0.2
Remove specific version of FSharp.Core.dll, support for VS2013.
Return replaced with Pure
Files Applicative.fs Monad.fs MonadPlus.fs and Comonad.fs merged into Functor.fs