ghc-7.6 updates

I changed the upper bounds on the dependencies and repaired trivia to do with `Prelude.catch` and `Data.Monoid.(<>)`.  

The first several tests work, but there is a failure with 

    TEST "examples/MergeSort.hs"
    type-checking failed:
    Missing type synonym Vec in binding merge

It's hard to see how any of the packages changed I put in the .cabal file could have cause this.  The `she` package is also failing, by the way, because of the (implicit) import of `Prelude.catch` in `src/Imports.lhs`