atlas: update to version 3.10.1

This patch fixes issue #297.
atlas: allow users to override the CPU configuration used to build ATLAS
haskell-heist: jailbreak to support the latest version of 'errors'
haskell-contravariant: update to version 0.4
haskell-either: update to version 3.4
haskell-errors: update to version 1.4.1
haskell-ghc-heap-view: update to version 0.4.2.0
haskell-hamlet: update to version 1.1.6.1
haskell-happstack-server: update to version 7.1.2