Ported the G-code generator from Perl to C++.

Removed GCode.pm
Removed the Perl bindigns for AvoidCrossingPerimeters, OozePrevention, SpiralVase, Wipe
Changed the std::set of extruder IDs to vector of IDs.
Removed some MSVC compiler warnings, removed obnoxious compiler warnings when compiling the Perl bindings.

xs/src/libslic3r/BridgeDetector.hpp

@@ -37,6 +37,9 @@ public:
     Polylines unsupported_edges(double angle = -1) const;
     
 private:
+    // Suppress warning "assignment operator could not be generated"
+    BridgeDetector& operator=(const BridgeDetector &);
+
     void initialize();
 
     struct BridgeDirection {