[saga-rg] open() and open_dir()

Hi, Another point regarding the open() and openDir() methods. This complicates this bit of the specification more than necessary. Graeme -3.36 Why are the methods open() and openDir() replicated between directory, logical_directory and ns_directory which they inherit? Removing these methods from ns_directory would resolve the issue regarding the multiple open_flag and open_dir_flags enumerations, otherwise these methods could be removed from logical_directory and ns_directory.