Create data folder if it does not exists yet

If the current sketch has a data folder, it tried to copy the data files
to the new location. But this folder was not yet created, which resulted
in trying to copy the files to a path that doesn't exists.

Now the folder gets created if it does not exists. So the files can be
copied.

Author: jeroenoverman

arduino-core/src/processing/app/Sketch.java

@@ -357,6 +357,12 @@ public void saveAs(File newFolder) throws IOException {
     if (getDataFolder().exists()) {
       System.out.println("Data folder is found and exists.");
       File newDataFolder = new File(newFolder, "data");
+      // Create the data folder
+      if (!newDataFolder.mkdirs()) {
+        String msg = I18n.format(tr("Could not create directory \"{0}\""), newFolder.getAbsolutePath());
+        throw new IOException(msg);
+      }
+      // Copy the data files into the new folder
       FileUtils.copy(getDataFolder(), newDataFolder);
     }