* lib/eval-config.nix: combined "configuration" and "extraModules"

  into one argument "modules".
* release.nix: fixed the manual job.
* ISO generation: break an infinite recursion.  Don't know why this
  suddenly happens.  Probably because of the nixpkgs.config change,
  but I don't see why.  Maybe the option evaluation is too strict.

svn path=/nixos/trunk/; revision=16878