implement uacomment config parameter

which can add comments to user agent as per BIP-0014

src/net.cpp

@@ -445,7 +445,7 @@ void CNode::PushVersion()
     else
         LogPrint("net", "send version message: version %d, blocks=%d, us=%s, peer=%d\n", PROTOCOL_VERSION, nBestHeight, addrMe.ToString(), id);
     PushMessage("version", PROTOCOL_VERSION, nLocalServices, nTime, addrYou, addrMe,
-                nLocalHostNonce, FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, std::vector<string>()), nBestHeight, true);
+                nLocalHostNonce, FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, mapMultiArgs.count("-uacomment") ? mapMultiArgs["-uacomment"] : std::vector<string>()), nBestHeight, true);
 }
 
 

src/rpcnet.cpp

@@ -444,7 +444,7 @@ UniValue getnetworkinfo(const UniValue& params, bool fHelp)
     UniValue obj(UniValue::VOBJ);
     obj.push_back(Pair("version",       CLIENT_VERSION));
     obj.push_back(Pair("subversion",
-        FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, std::vector<string>())));
+        FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, mapMultiArgs.count("-uacomment") ? mapMultiArgs["-uacomment"] : std::vector<string>())));
     obj.push_back(Pair("protocolversion",PROTOCOL_VERSION));
     obj.push_back(Pair("localservices",       strprintf("%016x", nLocalServices)));
     obj.push_back(Pair("timeoffset",    GetTimeOffset()));