* glom/application.[h|cc]: Remove unused (and unnecessary since the new
initial dialog) on_menu_file_open() and on_menu_file_close() overrides
and ui_file_select_open_with_browse().
* glom/dialog_existing_or_new.cc: on_select_clicked(): Use
Hildon::FileChooserDialog on Maemo.
* glom/bakery/app_withdoc_gtk.cc: Remove the uncommented undef of
GLOM_ENABLE_MAEMO - no more nasty hacks please. Instead comment-out
the set_menu() call with a TODO, leaving the rest of the maemo-specific
code working.