Renamed udev to udev166

This renaming prepares the landing of several versions of udev which are
required to boot old Linux versions.
The udev expression is mapped to udev166.

svn path=/nixpkgs/trunk/; revision=27718

pkgs/top-level/all-packages.nix

@@ -5656,7 +5656,8 @@ let
     cross = assert crossSystem != null; crossSystem;
   };
 
-  udev = callPackage ../os-specific/linux/udev { };
+  udev166 = callPackage ../os-specific/linux/udev/166.nix { };
+  udev = udev166;
 
   uml = import ../os-specific/linux/kernel/linux-2.6.29.nix {
     inherit fetchurl stdenv perl mktemp module_init_tools;