Fresh checkout of SHE darcs repo.

Latest darcs commit is

  Sun Apr 22 05:01:57 PDT 2012  conor@strictlypositive.org
    * guff
Make SHE work with GHC 7.6.

System.IO.Error.catch became catchIOError:

  http://hackage.haskell.org/packages/archive/base/4.5.1.0/doc/html/src/System-IO-Error.html#catchIOError

and no longer exists in the current GHC base package.