[PD] fix property issues

- Helix: the property Turns has the App::PropertyFloatConstraint thus also the pointer to it must have the same property

- LinearPattern and Helix: make constraints static class member (forgot this in commit 114bdf6b)

- Draft: make the constraint const

- PolarPattern and LinearPattern assure that the header file is loaded at last to avoid potential troubles

src/Mod/PartDesign/App/FeaturePolarPattern.cpp

@@ -31,8 +31,6 @@
 # include <BRepAdaptor_Curve.hxx>
 #endif
 
-
-#include "FeaturePolarPattern.h"
 #include "DatumLine.h"
 #include <Base/Axis.h>
 #include <Base/Exception.h>
@@ -41,6 +39,8 @@
 #include <Mod/Part/App/Part2DObject.h>
 #include <App/OriginFeature.h>
 
+#include "FeaturePolarPattern.h"
+
 using namespace PartDesign;
 
 namespace PartDesign {