Deprecation warnings should not be used in Nixpkgs because they spam innocent "nix-env -qa" users with (in this case) dozens of messages that they can't do anything about. This also reverts commit 2ca8833383.
2ca8833383
svn path=/nixpkgs/trunk/; revision=12278
svn path=/nixpkgs/trunk/; revision=12276
svn path=/nixpkgs/trunk/; revision=11455