Forward to more nodes documents written by ourselves

When a node receives or produces a document, it is forwarded back to the network. Currently, the forwarding is always the same: select X member nodes and Y non-member nodes, and forward the document to them.

But we could differentiate 2 cases:

• self document forwarding
• others document forwarding

Because we really want our personal documents to be shared, we can largely spread them on the network.

So for example, instead of sharing a newly produced block to 4-5 member nodes, we could double this number to share the block to almost 10 member nodes. This would avoid the block to not being shared, or partially shared, because we did not have chance on 4-5 nodes we selected which only 1 was available, and was a corrupted one.