QmlDesigner: adding a nice dialog for warnings

This patch also includes options to turn the warnings off.

Change-Id: I540bc19f5a4f23f441af0fd08b072dbcbf067a20
Reviewed-by: Marco Bubke <marco.bubke@digia.com>
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>

src/plugins/qmldesigner/qmldesignerplugin.cpp

@@ -369,8 +369,9 @@ void BauhausPlugin::switchTextDesign()
     }
 }
 
-DesignerSettings BauhausPlugin::settings() const
+DesignerSettings BauhausPlugin::settings()
 {
+    m_settings.fromSettings(Core::ICore::settings());
     return m_settings;
 }