Firewall class manifests

Manifests for managing the required packages and services on supported Linux
operating systems. These will be required for persistence.
Firewall and firewallchain persistence

Call the necessary commands from the provider to persist rules between
reboots. Tested on the following distros:

- CentOS 5.8
- CentOS 6.3
- Ubuntu 10.04
- Ubuntu 12.04
- Debian 6

Cavaets:

- Persistence may fail on the first run if Firewall resources are actioned
  before the Package resource.
- Older iptables-persistent doesn't support the restoration of ip6tables.
- ebtables cannot be restored.
Merge pull request #133 from dcarley/native_persistence

Native persistence