Properly copy extern bin folder in Playground

projects/nat-flixel-desktop-playground/Project.xml

@@ -30,7 +30,8 @@
 	<set name="BUILD_DIR" value="export" />
 	<classpath name="source" />
 	<assets path="assets" />
-	<prebuild command="mkdir bin" />
+	<!-- IMPORTANT: This copies the #extern scripts generated by NAT into the project output folders: -->
+	<postbuild command="copy-extern-scripts.sh" />
 	<!-- _______________________________ Libraries ______________________________ -->
 
 	<haxelib name="flixel" />

projects/nat-flixel-desktop-playground/copy-extern-scripts.sh

@@ -0,0 +1,8 @@
+#! /bin/bash
+
+for dir in export/**/bin; do
+    if [ -d $dir/bin ]; then
+        rm -rf $dir/bin
+    fi
+    cp -r bin $dir/bin
+done