Remove timestamp from the kernel.
Make initrd and the kernel builds repeatable.
Merge branch 'make-the-kernel-build-repeatable' of git://github.com/alexanderkjeldaas/nixpkgs

Make the kernel build and initrd generation binary repeatable (#2128)
buildPythonPackage: don't return on shellHook

Entering environment might not always be the desired effect.
Added a derivation for Ozgun's's retry (Haskell.)
Merge pull request #2157 from fmap/haskell-retry

Added a derivation for Ozgun's's retry (Haskell.)
haskell-criterion: downgrade to hastache 0.5.1 to fix the build

Closes <https://github.com/NixOS/nixpkgs/pull/2133>.