Create the instance of MessengerWindow only when needed and delete it on close.

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@3301 b45a01b8-16f6-495d-af2f-9b41ad6348cc

retroshare-gui/src/gui/notifyqt.cpp

@@ -24,6 +24,22 @@
  * #define NOTIFY_DEBUG
  ****/
 
+/*static*/ NotifyQt *NotifyQt::_instance = NULL;
+
+/*static*/ NotifyQt *NotifyQt::Create ()
+{
+    if (_instance == NULL) {
+        _instance = new NotifyQt ();
+    }
+
+    return _instance;
+}
+
+/*static*/ NotifyQt *NotifyQt::getInstance ()
+{
+    return _instance;
+}
+
 void NotifyQt::notifyErrorMsg(int list, int type, std::string msg)
 {
 	emit errorOccurred(list,type,QString::fromStdString(msg)) ;