Broadcast to All User's Subscriptions

[stuartmscott]

A user may subscribe to multiple storage providers, some of which may not be in the miner's set of peers.

Once a miner creates a new block, they must broadcast it to the union of the set of its peers and the set of providers to which the user is subscribed. The later can be determined by traversing the financego.Subscription blockchain to find all subscriptions to which the user has access and looking at the other aliases which have access to those subscriptions.