adds a function:

void gtk_file_selection_set_show_hidden_files(gboolean);

to gtkfilesel.c, which set whether hidden (.) files should be displayed in
the file and dir lists.
also adds a toggle button in testgtk to test it.

I have emailed owen with this patch as well.

Mick.

(mslade@cit.nepean.uws.edu.au)