WIP: Moved sources int src/, separated most of the source code from Perl.

The XS was left only for the unit / integration tests, and it links
libslic3r only. No wxWidgets are allowed to be used from Perl starting
from now.

src/libslic3r/GCode/PostProcessor.hpp

@@ -0,0 +1,15 @@
+#ifndef slic3r_GCode_PostProcessor_hpp_
+#define slic3r_GCode_PostProcessor_hpp_
+
+#include <string>
+
+#include "../libslic3r.h"
+#include "../PrintConfig.hpp"
+
+namespace Slic3r {
+
+extern void run_post_process_scripts(const std::string &path, const PrintConfig &config);
+
+} // namespace Slic3r
+
+#endif /* slic3r_GCode_PostProcessor_hpp_ */