Bugfix: lack of strong type checking when passing arrayref objects to XS caused random lack of infill. Now added strong type checking for all XS entities. Also fixes a potential issue with bridges caused by the same error. #1652

Conflicts:

	lib/Slic3r/Layer/Region.pm

xs/src/Polyline.hpp

@@ -20,6 +20,7 @@ class Polyline : public MultiPoint {
     void simplify(double tolerance);
     
     #ifdef SLIC3RXS
+    void from_SV_check(SV* poly_sv);
     SV* to_SV_ref();
     SV* to_SV_clone_ref() const;
     #endif