Move EventFilteringMainWindow to utils

Also rename it to AppMainWindow. We add some more functionality to
it in following patches.

Change-Id: I752ccd07759eaaf6a2e96ec758e35b595bf788a2
Reviewed-by: Eike Ziller <eike.ziller@nokia.com>

src/plugins/coreplugin/mainwindow.h

@@ -33,10 +33,11 @@
 #ifndef MAINWINDOW_H
 #define MAINWINDOW_H
 
-#include "eventfilteringmainwindow.h"
 #include "icontext.h"
 #include "icore.h"
 
+#include <utils/appmainwindow.h>
+
 #include <QMap>
 #include <QColor>
 
@@ -80,7 +81,7 @@ class StatusBarManager;
 class VersionDialog;
 class SystemEditor;
 
-class MainWindow : public EventFilteringMainWindow
+class MainWindow : public Utils::AppMainWindow
 {
     Q_OBJECT