pkgs: Move mongooseim into its own subdir.

We're going to add patches, so it's a good idea to not mess up the pkgs
directory with all those files.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
mongooseim: Nix-specific patch for reltool.config.

This removes the directory for $out/var/log, but the primary goal is to
avoid bundling OTP within MongooseIM's store path and use the one
already on the target system.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
mongooseim: Log using journald instead of logfile.

This patch removes logging to any files and prints all warning and
errors to stderr instead, so it gets picked up by journald.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
lighttpd: Move into modules/services.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
mongooseim: Add new service module.

Right now, this is only a basic service which creates a new Mnesia
database in the home directory of the "mongoose" user. It neither uses
hot code reloading nor is it particularily secure at the moment or
allows for flexible configuration.

But what works is running a basic XMPP server without too fancy
configuration.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
hydra: Add kvm and nixos-test to all build slaves.

This only adds the features to the hydra machine, regardless on whether
the slave machines actually support it. But as we only have one slave
machine and it's using a NixOS default kernel, those features are indeed
supported.

Let's accurately detect this when we actually need to differentiate the
slave machines and their features.

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