CH10: intro edits

- We revise sentence about equality among peers to make it clear that
  the peers are full nodes.  Clients are not peers of a full node.

- Remove clause about "reciprocity" being the incentive for
  participation.  I think there are varied reasons for operating a full
  node, ranging from wanting to validate your own transactions
  (requiring only a pruning full node) to wanting to keep mining
  decentralized (e.g. by relaying transactions).

- Drop line about non-Bitcoin-P2P protocols being "extended Bitcoin
  network".  I think that's an unnecessary categorization.

ch08.asciidoc

@@ -6,18 +6,18 @@
 ((("Bitcoin network", "peer-to-peer architecture")))((("peer-to-peer
 (P2P)")))Bitcoin is structured as a peer-to-peer network architecture on
 top of the internet. The term peer-to-peer, or P2P, means that the
-computers that participate in the network are peers to each other, that
-they are all equal, that there are no "special" nodes, and that all
-nodes share the burden of providing network services. The network nodes
+full nodes which participate in the network are peers to each other, that
+they can all equal, and that there are no "special" nodes.
+The network nodes
 interconnect in a mesh network with a "flat" topology. There is no
 server, no centralized service, and no hierarchy within the network.
 Nodes in a P2P network both provide and consume services at the same
-time with reciprocity acting as the incentive for participation. P2P
+time. P2P
 networks are inherently resilient, decentralized, and open. A preeminent
 example of a P2P network architecture was the early internet itself,
 where nodes on the IP network were equal. Today's internet architecture
 is more hierarchical, but the Internet Protocol still retains its
-flat-topology essence. Beyond Bitcoin, the largest and most successful
+flat-topology essence. Beyond Bitcoin and the internet, the largest and most successful
 application of P2P technologies is file sharing, with Napster as the
 pioneer and BitTorrent as the most recent evolution of the architecture.
 
@@ -25,22 +25,20 @@ Bitcoin's P2P network architecture is much more than a topology choice.
 Bitcoin is a P2P digital cash system by design, and the network
 architecture is both a reflection and a foundation of that core
 characteristic. Decentralization of control is a core design principle
-that can only be achieved and maintained by a flat, decentralized P2P
+that can only be achieved and maintained by a flat and decentralized P2P
 consensus network.
 
 ((("Bitcoin network", "defined")))The term "Bitcoin network" refers to
 the collection of nodes running the Bitcoin P2P protocol. In addition to
-the Bitcoin P2P protocol, there are other protocols such as Stratum that
+the Bitcoin P2P protocol, there are other protocols that
 are used for mining and lightweight or mobile wallets. These additional
 protocols are provided by gateway routing servers that access the
 Bitcoin network using the Bitcoin P2P protocol and then extend that
 network to nodes running other protocols. For example, Stratum servers
 connect Stratum mining nodes via the Stratum protocol to the main
 Bitcoin network and bridge the Stratum protocol to the Bitcoin P2P
-protocol. We use the term "extended Bitcoin network" to refer to the
-overall network that includes the Bitcoin P2P protocol, pool-mining
-protocols, the Stratum protocol, and any other related protocols
-connecting the components of the Bitcoin system.
+protocol. We will describe some of the most commonly used of those
+protocols in this chapter in addition to Bitcoin's P2P protocol.
 
 === Node Types and Roles