Setting $TZDIR to ${pkgs.tzdata}/share/zoneinfo can cause logged-in
sessions to refer to a garbage-collected zoneinfo directory. So use
/etc/zoneinfo instead.
We don't need to set $TZ, because we have /etc/localtime. In fact,
setting $TZ without $TZDIR doesn't work anymore since Glibc no longer
contains zone info.
empty now), do more of bashrc.sh declaratively, and moved nsswitch
generation to modules/config/nsswitch.nix.
svn path=/nixos/branches/modular-nixos/; revision=15754