overrides: Remove override for Erlang manpages.

Applied upstream at NixOS/nixpkgs@ec65a1e.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
common: Include modules using module-list.

This also means that we now have to explicitly enable a certain feature,
such as vuizvui.i3 (which is the only module right now).

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
i3/conky: Don't even try to use X for output.

I've already disabled most output types, but just to be sure.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
i3/conky: Add a new "single" layout.

This is for machines that don't have multiple heads attached, such as
arilou or kzerza.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
i3: Use Nix expressions to generate status bars.

We might break the dnyarri/mmrnmhrm setup here, but it is mainly for
getting rid of the hack to match networking.hostName for a particular
node in order to swap heads.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
i3: Fix generating config for a single head.

If there is only one head, we don't need any "workspace" command in the
i3 configuration file, so let's omit it entirely.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
i3: Add preliminary VM test.

Currently just sleeps for 20 seconds and takes a screenshot. Nothing too
fancy yet.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
release: Drop envs attribute.

I'm not using them anymore, except for the kernel env. And the latter
has so few dependencies that even the slowest machine shouldn't need
very long to compile.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
release: Add preliminary test for i3 module.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>