lnwire: document commitment+HTLC update msgs

This commit adds some cursory documentation along wit minor field
modifications to all messages which deal with adding HTLC’s, or
updating remote commitment transactions.

The messages for dual funding of channel is left purposefully
undocumented as all initial negotiations will be single funder by
default.

A revamp of the testing infrastructure of lnwire will be committed in
the near future.

server.go

@@ -209,6 +209,8 @@ func (s *server) listener(l net.Listener) {
 		srvrLog.Tracef("New inbound connection from %v", conn.RemoteAddr())
 		peer := newPeer(conn, s)
 		peer.Start()
+
+		s.newPeers <- peer
 	}
 
 	s.wg.Done()