gnunet: it was missing extraGroups
Set the domain name of the machine

The domain name was not being set before, even if the administrator
properly configured the networking.domain option in
/etc/nixos/configuration.nix.
openvpn.nix: Use systemd.*

Also add an option ‘autoStart’ to configure whether an OpenVPN
instance should be started automatically.  And don't log to
/var/log/openvpn-* anymore.
apparmor: Fix broken iputils/ping profile
apparmor: Fix loading multiple profiles

apparmor's systemd service wasn't working when multiple profiles were
defined, due to the ExecStart commands in the service file being
broken into multiple lines, instead of being separated by ';'.
apparmor: Fix service stop

When stopping the apparmor service, the profile removal failed with
parsing errors due to not including the
${pkgs.apparmor}/etc/apparmor.d directory.
add networkmanager_openvpn to systemPackages
Merge pull request #172 from wizeman/apparmor-ping

apparmor: Fix broken iputils/ping profile
Merge pull request #173 from wizeman/apparmor-service

Apparmor service fixes
Merge pull request #167 from wizeman/domain

Set the domain name of the machine
atd: don't enable at daemon by default

The at daemon doesn't work on NixOS [1], so enabling it by default
doesn't seem useful. I'd argue that it shouldn't be enabled by default
even if it worked, actually.

[1] http://lists.science.uu.nl/pipermail/nix-dev/2013-April/011048.html