Add in a few extra plugins

plugins/IrcClientPlugin/pingmessagehandler.cpp

@@ -0,0 +1,11 @@
+#include "pingmessagehandler.h"
+
+PingMessageHandler::PingMessageHandler()
+{
+}
+
+void PingMessageHandler::handle(Client *client, const Message &message)
+{
+    QString pongMessage = message.getTarget();
+    client->sendPong(pongMessage);
+}