GtkFileChooser supports overwrite-confirm

Since GTK version 2.8 (in 2005), GtkFileChooser has had a method gtk_file_chooser_set_do_overwrite_confirmation(). If set, when the user chooses to save to an existing file name, it alerts the user with the options of overwriting or canceling.

Shortly before the release of GTK 2.8.0, Balsa implemented its own functionally equivalent version. I feel that the GTK implementation has now proved its stability, and that Balsa should be ported to it.

Opinions?