Limit "Only retract when crossing perimeters" so that retraction is triggered also when crossing the boundaries of a single region. #2298

xs/src/libslic3r/Layer.hpp

@@ -90,6 +90,7 @@ class Layer {
     LayerRegion* add_region(PrintRegion* print_region);
     
     void make_slices();
+    template <class T> bool any_internal_region_slice_contains(const T &item) const;
 
     protected:
     int _id;     // sequential number of layer, 0-based