[Nix-dev] udev update

[Yury G. Kudryashov]

Hi!

I've just created udev-173 branches in nixpkgs and nixos. Could you please 
test them? The list of changes:
 * udev-173
 * configure udev with --libexec=$out/lib/udev to be closure to upstream
 * upstream thinks that setting rules dir in config file is only useful for 
testing. Fix it (see patch in os-specific/linux/udev)
 * fix paths to RUN+= and IMPORT{program} programs.

I consider this a small feature branch, and I'm going to merge it in 3 days 
unless someone objects.
-- 
Yury G. Kudryashov,
mailto: urkud at mccme.ru