A little Script Creator work and little checks. (#9)

* No builds allowed here.

* Try something.

* Next work.

* Add some Logging stuff for testing purpose.

* Ok, this should log it priperly.

* Replace MainMenu with Screen Selection.

* Redo Screen Logic.

* Switch back to old MainMenu.

* Only access Scriptlist, when Scripts are found.

Hopefully avoid crashes with that.

* Remove unused String, because we use the MainMenu again.

source/screens/ftpScreen.cpp

@@ -86,7 +86,7 @@ void FTPScreen::Draw(void) const
 	memset(ftp_file_transfer, 0, 50); // Empty transfer status.
 	ftp_exit();
 
-	Gui::screenBack();
+	Screen::back();
 	return;
 }