RPC help documentation for addnode peerinfo.

Also adds a comment about the netgroup exclusion behavior.

src/net.cpp

@@ -1633,6 +1633,11 @@ void CConnman::ThreadOpenConnections()
             LOCK(cs_vNodes);
             BOOST_FOREACH(CNode* pnode, vNodes) {
                 if (!pnode->fInbound && !pnode->fAddnode) {
+                    // Netgroups for inbound and addnode peers are not excluded because our goal here
+                    // is to not use multiple of our limited outbound slots on a single netgroup
+                    // but inbound and addnode peers do not use our outbound slots.  Inbound peers
+                    // also have the added issue that they're attacker controlled and could be used
+                    // to prevent us from connecting to particular hosts if we used them here.
                     setConnected.insert(pnode->addr.GetGroup());
                     nOutbound++;
                 }

src/rpc/net.cpp

@@ -92,6 +92,7 @@ UniValue getpeerinfo(const JSONRPCRequest& request)
             "    \"version\": v,              (numeric) The peer version, such as 7001\n"
             "    \"subver\": \"/Satoshi:0.8.5/\",  (string) The string version\n"
             "    \"inbound\": true|false,     (boolean) Inbound (true) or Outbound (false)\n"
+            "    \"addnode\": true|false,     (boolean) Whether connection was due to addnode and is using an addnode slot\n"
             "    \"startingheight\": n,       (numeric) The starting height (block) of the peer\n"
             "    \"banscore\": n,             (numeric) The ban score\n"
             "    \"synced_headers\": n,       (numeric) The last header we have in common with this peer\n"