* nsfns.m (ns_filename_from_panel, ns_directory_from_panel): New

* nsfns.m (ns_filename_from_panel, ns_directory_from_panel): New
functions.
(Fns_read_file_name): ret is BOOL.  If ! dir_only_p, don't choose
directories.  If filename is nil, get directory name.
Use getFilename and getDirectory.
(getFilename, getDirectory): New methods for EmacsSavePanel and
EmacsOpenPanel.
(ok:): In EmacsOpenPanel, if we can't choose directories, just return.

* nsterm.h (EmacsSavePanel, EmacsOpenPanel): Add getFilename
and getDirectory.

Fixes: debbugs:13932