Ported ModelObject::rotate() and ModelObject::flip() to XS, as well as axes constants

xs/xsp/Geometry.xsp

@@ -87,4 +87,16 @@ simplify_polygons(polygons, tolerance)
     OUTPUT:
         RETVAL
 
+IV
+_constant()
+  ALIAS:
+    X           = X
+    Y           = Y
+    Z           = Z
+  PROTOTYPE:
+  CODE:
+    RETVAL = ix;
+  OUTPUT: RETVAL
+
 %}
+

xs/xsp/Model.xsp

@@ -182,6 +182,8 @@ ModelMaterial::attributes()
     void translate(double x, double y, double z);
     void scale_xyz(Pointf3* versor)
         %code{% THIS->scale(*versor); %};
+    void rotate(float angle, Axis axis);
+    void flip(Axis axis);
     
     Model* cut(double z)
         %code%{

xs/xsp/my.map

@@ -184,6 +184,7 @@ Clone<BridgeDetector>      O_OBJECT_SLIC3R_T
 
 GLVertexArray*             O_OBJECT_SLIC3R
 
+Axis                  T_UV
 ExtrusionLoopRole     T_UV
 ExtrusionRole     T_UV
 FlowRole     T_UV

xs/xsp/typemap.xspt

@@ -173,6 +173,12 @@
 %typemap{SupportLayerPtrs*};
 
 
+%typemap{Axis}{parsed}{
+  %cpp_type{Axis};
+  %precall_code{%
+    $CVar = (Axis)SvUV($PerlVar);
+  %};
+};
 %typemap{SurfaceType}{parsed}{
   %cpp_type{SurfaceType};
   %precall_code{%