Feature Request - Implement Master Key

[coolacid]

It would be wise that when creating a new network, a master key be created on the first node. This master key could then be used to sign additional keys for use by network maintainers.

Reasoning; With SecureDHT permanent keys, if a node loses it's key, it would be very nice for a network admin to be able to delete these keys using either the master key, or a key signed by the master key.