should not rely on its existence in deciding whether to use
getpwuid(). Not using getpwuid() causes rcs to fail with "ci:
setuid not supported".
svn path=/nixpkgs/trunk/; revision=19957
URLs to http://nix.cs.uu.nl/dist/tarballs. With content-addressable
mirror support (r9190, NIXPKGS-70) this is no longer necessary:
fetchurl will try to download from that location automatically. So
we can keep the original URLs.
svn path=/nixpkgs/trunk/; revision=9192
