p2p perf send a notice of large blocks/txns

[pmesnier]

Relates to #291. There is already a notice message, but it isn't being used in the manner described in #291. What I have is a notice message that is only used for transactions and then all recipients immediately turn around and request the contents right away. I'm not entirely sure of the benefit with blocks, since they have to be shared anyway

[pmesnier]

Marking for M2. There is more discussion required to decide if this issue needs more work or is satisfied by the current code.

[pmesnier]

I think this issue is settled. There is a "just send it" max payload size value of 3 times my guess of the default MTU size, 1300 bytes. 3x because that is the minimum bandwidth cost of notify / request / deliver.

A new ticket should be opened if more work is needed.