Rewrote Fill2.pm to C++, deleted Perl infills for good.

Removed dependency on Perl Math::PlanePath module.
Fixed compilation with Visual Studio and SLIC3R_DEBUG: Visual Studio older than 2015 does not support the prinf type specifier %zu. Use %Iu instead.
C++11 move semantics enabled.

xs/src/libslic3r/Fill/Fill.hpp

@@ -13,7 +13,8 @@
 
 namespace Slic3r {
 
-class Surface;
+class ExtrusionEntityCollection;
+class LayerRegion;
 
 // An interface class to Perl, aggregating an instance of a Fill and a FillData.
 class Filler
@@ -28,6 +29,8 @@ public:
     FillParams   params;
 };
 
+void make_fill(LayerRegion &layerm, ExtrusionEntityCollection &out);
+
 } // namespace Slic3r
 
 #endif // slic3r_Fill_hpp_