Fix ambiquity due to generalised `elem`

In base-4.8, `elem` has been generalised to `Foldable`, so in
combination with `-XOverloadedStrings`, something like `\c -> elem c
"abc"` can't be type-inferred anymore.
Bump deepseq & time deps

This is needed for GHC 7.10 compat
Properly decode utf-8 pathnames inside fileserve. Closes #220.
Merge commit 'a9cb42103d38df03466497b1b2974f7589eda327'
Merge commit '9de253841e763e71d988c5fb60d60ebed1fe7dc4'
Merge branch '0.9-stable'