Merge pull request #834 from snoyberg/master

Yesod updates for GHC 7.8
Fix minor bugs with installer (mongodb should work properly now)
Merge branch 'master' of https://github.com/TechEmpower/FrameworkBenchmarks
Some Yesod cleanup/optimization

* Use sendWaiResponse
* Simplify the Mongo code to avoid persistent-mongoDB
* Avoid InternalState acquisition
* Use runInUnboundThread for Yesod
Use stylish-haskell on yesod.hs
Update WAI to use GHC 7.8

Pinging @kazu-yamamoto
Pass in explicit core count from threads variable

Pinging @kazu-yamamoto does this make sense to you?
REVERT ME: Just run WAI and Yesod