chromium: Remove .py[co] files prior to building.

Thanks to @iElectric for the notification, although I'm not really sure
whether this will fix the following failed Hydra build:

http://hydra.nixos.org/build/17609086/nixlog/1/raw

The reason is that this failure doesn't happen on every build, but let's
see whether it will happen again now.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
grsecurity: Update stable and test patches

stable: 3.0-3.14.25-201411231452 -> 3.0-3.14.25-201411260106
test:   3.0-3.17.4-201411231452  -> 3.0-3.17.4-201411260107
nixos/services.openssh: Allow knownHost keys to have multiple lines.

Useful for adding several public keys of different types for the same host.
nixos: Rename virtualbox to virtualboxGuest.

Especially new users could be confused by this, so we're now marking
services.virtualbox.enable as obsolete and defaulting to
services.virtualboxGuest.enable instead. I believe this now makes it
clear, that this option is for guest additions only.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
nixos: Add enable option for programs/virtualbox.

We will simply rename the previous module and add a warning whenever the
module is included directly, pointing the user to the right option and
also enable it as well (in case somebody has missed the option and is
wondering why VirtualBox doesn't work anymore).

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
nixos/sshd: Fix build if knownHosts is empty.

Introduced by 77ff279f2767cf1f28eed03a1f93e5df54c99bf5.

Build failure: https://headcounter.org/hydra/build/583158/nixlog/5/raw

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
nixos: reverse logic in nixos interactive tests documentation
fix printing test
sselp prints X selection to standard out