Display the cluster id in the footer, when clustering is enabled

It's very common to use a hack to show the current cluster node in the footer right now. This is usually done by customizing the version.properties file, but as the name suggest, that's not what this file is supposed to be for.

The idea would be to start displaying the cluster id in the footer by default (when clustering is enabled) so that we don't need to do this kind of hack anymore.