Added Perl to C++ interfaces for creating the preset editor pages

from C++ and to add debugging menus from C++. These lightweigth
interfaces should help new team members to hack the UI without
a Perl knowledge.

xs/src/slic3r/GUI/GUI.hpp

@@ -4,6 +4,11 @@
 #include <string>
 #include <vector>
 
+class wxApp;
+class wxFrame;
+class wxMenuBar;
+class wxNotebook;
+
 namespace Slic3r { namespace GUI {
 
 void disable_screensaver();
@@ -12,6 +17,16 @@ std::vector<std::string> scan_serial_ports();
 bool debugged();
 void break_to_debugger();
 
+// Passing the wxWidgets GUI classes instantiated by the Perl part to C++.
+void set_wxapp(wxApp *app);
+void set_main_frame(wxFrame *main_frame);
+void set_tab_panel(wxNotebook *tab_panel);
+
+void add_debug_menu(wxMenuBar *menu);
+// Create a new preset tab (print, filament or printer),
+// add it at the end of the tab panel.
+void create_preset_tab(const char *name);
+
 } }
 
 #endif