Create method for initial replication

This is still open for debate.

It could be done fully automated from the master which pushes the initial content. This is by far the most difficult solution.

It could be done completely manual, by copying the database and deleting the unwanted content or by exporting the content to xml which has to be replicated from the master and import the xml at the slave.

It could be done semi-automatically. For example all content is copied to the slave (db copy) and some code is run on the slave to delete the unwanted content which can use the same filter config as the replicator itself.