Block service commands inside chrooted environment

While new LXC container is being configured, certain services might be
started, stopped or restarted. To prevent this and have them
misconfigured as a result, during chroot configuration service commands
will be disabled.
Add Salt integration for LXC containers

Salt minion can be automatically installed and enabled in the LXC
container (this functionality is disabled by default). It will start on
container boot and try to contact Salt master server and register there.

You can optionally pass configuration options to Salt minion as a YAML
text block, they will be saved in '/etc/salt/minion.d/ansible.conf'
inside the container.
Merge pull request #7 from drybjed/salt-integration

Salt integration, service start prevention in chroot