NancyFx/Nancy — pull request #1759 by Crisfole (2014-12-03 19:08:43+00:00)
Title: Async user mapper

Adds Tests For [PR 1643](https://github.com/NancyFx/Nancy/pull/1643). Also "Nancy-ifies" the code to keep it stylistically similar to the rest of Nancy. (Only one small change). It fixes a bug in the otherwise excellent implementation provided by @ExUltima (the UserMapper was still required even if an Async one existed).