#72 TTL, Node Hops

[Neil Avery]

* Time To Update (TTU): each peer checks if its
known peers are available when TTU expires. By default,
its value is 1 minutes.
* Number Of Acquaintances (NOA): is the minimal
number of peers one peer needs to know to keep up the
infrastructure. By default, its value is 10 peers.
* Time To Live (TTL): in hops for JVMs (node) depth
search (acquisition). By default, its value is 5 hops.