Work around apt-get issues (c/o @codygman)

See:
https://github.com/TechEmpower/FrameworkBenchmarks/pull/834#issuecomment-57629157
GHC 7.8
Clean up Yesod code with stylish-haskell
yesod 1.4 and disable non-raw MongoDB
Set the LANG environment variable
Some Yesod (attempted) optimizations