Untie the core functionality from Wai.

Wai specific functionality is now in the module Network.Wai.OAuth.Wai.
Eventually, the base package will be renamed and the Wai specifics moved
into a separate package.

Additionally, cutting ties with Wai also shaves off the StateT layer off
the monad stack.
Removing duplicated function.
More Haddock documentation.
Organize imports.
Some more docs.
Minor cleanup + comments for clarity.
Cleanup tests.
Fix hostPortParser in N.W.O.Wai
Make the example output a bit more clear