QmlDesigner.Instances: emit component complete signal for 5.1

Emitting the Component.onComplete signal.

This is only available in Qt 5.1

Change-Id: I77503333296cccd9999d2610cca126530f777777
Reviewed-by: Marco Bubke <marco.bubke@digia.com>

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/graphicalnodeinstance.cpp

@@ -12,6 +12,8 @@
 #include <private/qquicktextinput_p.h>
 #include <private/qquicktextedit_p.h>
 
+#include <designersupport.h>
+
 namespace QmlDesigner {
 namespace Internal {
 
@@ -499,6 +501,10 @@ void GraphicalNodeInstance::doComponentComplete()
 
     disableTextCursor(quickItem());
 
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 1, 0))
+    DesignerSupport::emitComponentCompleteSignalForAttachedProperty(quickItem());
+#endif
+
     quickItem()->update();
 }