Update Vagrant to 1.5.2
Update VirtualBox to 4.3.10
Update to GHC 7.8.1 and Cabal 1.18.0.3

These updates had to happen at the same time since I moved off of the
Haskell Platform.
Add GHC 7.8.1 to tested-with
Relax Criterion constraints
Update CHANGELOG.md
Merge branch 'refs/heads/ghc-7.8.1'