[refs #63] Fixing issue where submodules added were not being correctly initialised when updating servers
[refs #64] Adding collectd to all nodes, and configuring plugins for a few additional services where necessary
Merge branch 'feature/collectd' into develop
[refs #64] Fixing nameserver config
[refs #64] Using the common graphite server rather than assuming there si one on the current environment
Additional helper method for updating pcakages on servers