Execution abstraction and build fix for linux and mac

xs/src/slic3r/AppControllerWx.cpp

@@ -1,6 +1,7 @@
 #include "AppController.hpp"
 
 #include <thread>
+#include <future>
 
 #include <slic3r/GUI/GUI.hpp>
 #include <slic3r/GUI/PngExportDialog.hpp>
@@ -20,6 +21,11 @@
 
 namespace Slic3r {
 
+bool AppControllerBoilerplate::supports_asynch() const
+{
+    return true;
+}
+
 AppControllerBoilerplate::PathList
 AppControllerBoilerplate::query_destination_paths(
         const std::string &title,