Qt4/Qt5 neutral changes:

+ change inheritance of PropertyItem to not derive from BaseClass (and QObject) any more to fix crashes with Qt5

src/Mod/Sketcher/Gui/PropertyConstraintListItem.cpp

@@ -36,7 +36,7 @@
 using namespace SketcherGui;
 using namespace Gui::PropertyEditor;
 
-TYPESYSTEM_SOURCE(SketcherGui::PropertyConstraintListItem, Gui::PropertyEditor::PropertyItem)
+PROPERTYITEM_SOURCE(SketcherGui::PropertyConstraintListItem)
 
 PropertyConstraintListItem::PropertyConstraintListItem()
 {

src/Mod/Sketcher/Gui/PropertyConstraintListItem.h

@@ -43,7 +43,7 @@ namespace SketcherGui {
 class PropertyConstraintListItem: public Gui::PropertyEditor::PropertyItem
 {
     Q_OBJECT
-    TYPESYSTEM_HEADER();
+    PROPERTYITEM_HEADER
 
     virtual QWidget* createEditor(QWidget* parent, const QObject* receiver, const char* method) const;
     virtual void setEditorData(QWidget *editor, const QVariant& data) const;