Revert "Merge pull request #567 from MarcWeber/submit/cmake-improvement"

This reverts commit abc7591aaf3912d819401241d7d2339fb96441f3, reversing changes
made to 6b1ebeccf2c9d9e8f68d7e21a1e55b5d91577683, because they broke half the
packages in stdenv-updates: http://hydra.nixos.org/eval/927013 has further
details.