Implement Replicable Interface for Gossip Blacklists

[sahilTakiar]

apache-gossip has a Replicable interface that defines if a given message should be replicated from a src node to a dest node. We should be able to use this interface to implement blacklists.

[sahilTakiar]

There is actually a BlackListReplicable already, we just have to integrate with it.

[noah-]

integrate this with spam filter possibly?