More cleanup work for Evolution.  This patch makes significant progress
towards migrating off deprecated symbols in the GTK+ and GNOME libraries.
I'm also killing off several utility functions and macros that have become
redundant or unused over the years.

Here's the checklist:

- Fix all implicit function declarations.

- Port evolution-addressbook-export from popt to GOption.

- Drop GnomePropertyBox support in e-dialog-widgets.c (no longer needed).

- Migrate to non-deprecated symbols:

    GNOME_STOCK_xxx                      --> GTK_STOCK_xxx
    GTK_OBJECT_FLOATING()                --> g_object_is_floating()
    GTK_OBJECT_SET_FLAGS()               --> g_object_force_floating()
    GnomeDialog                          --> GtkDialog
    GnomeFileEntry                       --> GtkFileChooserButton
    GnomeIconTheme                       --> GtkIconTheme
    GnomeMessageBox                      --> GtkMessageDialog
    g_concat_dir_and_file()              --> g_build_filename()
    g_object_ref(), gtk_object_sink()    --> g_object_ref_sink()
    gnome_date_edit_get_date()           --> gnome_date_edit_get_time()
    gnome_init()                         --> gnome_program_init()
    gnome_window_set_icon_from_file()    --> gtk_window_set_icon_from_file()
    gtk_accel_group_unref()              --> g_object_unref()
    gtk_button_box_set_child_ipadding()  --> (nothing, use style properties)
    gtk_button_box_set_child_size()      --> (nothing, use style properties)
    gtk_button_box_set_spacing()         --> gtk_box_set_spacing()
    gtk_cell_renderer_editing_canceled() --> gtk_cell_renderer_stop_editing()
    gtk_draw_shadow()                    --> gtk_paint_shadow()
    gtk_entry_set_editable()             --> gtk_editable_set_editable()
    gtk_idle_add()                       --> g_idle_add()
    gtk_idle_remove()                    --> g_source_remove()
    gtk_label_get()                      --> gtk_label_get_text()
    gtk_layout_freeze()                  --> (nothing)
    gtk_layout_thaw()                    --> (nothing)
    gtk_marshal_NONE__INT                --> g_cclosure_marshal_VOID__INT
    gtk_menu_append()                    --> gtk_menu_shell_append()
    gtk_notebook_set_page()              --> gtk_notebook_set_current_page()
    gtk_radio_menu_item_group()          --> gtk_radio_menu_item_get_group()
    gtk_signal_connect_object()          --> g_signal_connect_swapped()
    gtk_timeout_add()                    --> g_timeout_add()
    gtk_timeout_remove()                 --> g_source_remove()
    gtk_type_new()                       --> g_object_new()
    gtk_widget_draw()                    --> (use GTK's implementation)
    gtk_widget_ref()                     --> g_object_ref()
    gtk_widget_set_usize()               --> gtk_widget_set_size_request()
    gtk_widget_unref()                   --> g_object_unref()

- Remove some unused utilities and macros:

    E_MAKE_X_TYPE
    E_OBJECT_CLASS_ADD_SIGNALS
    GET_DUPLICATED_STRING_ARRAY_FROM_ELLIPSIS
    GET_STRING_ARRAY_FROM_ELLIPSIS
    e_create_image_widget()
    e_make_widget_backing_stored()
    e_read_file()
    e_signal_connect_full_while_alive()
    e_signal_connect_while_alive()
    e_strsplit()
    e_write_file()
    e_writh_file_mkstemp()

- Remove some obsolete or unnecessary utilities:

    - E_OBJECT_CLASS_TYPE

        Replace with G_TYPE_FROM_CLASS.

    - e_strdup_strip()

        Replace with g_strstrip (g_strdup (str)).

    - e_free_object_list() / e_free_object_slist()

        Replace with:

          g_list_foreach (list, (GFunc) g_object_unref, NULL);
          g_list_free (list);

        Similarly for e_free_object_slist().

    - e_free_string_list() / e_free_string_slist()

        Replace with:

          g_list_foreach (list, (GFunc) g_free, NULL);
          g_list_free (list);

        Similarly for e_free_string_slist().

    - e_sort()

        Replace with g_qsort_with_data ().

    - e_button_new_with_stock_icon() / e_gtk_button_new_with_icon()

        Replace with gtk_button_new_from_stock(), or:

          button = gtk_button_new_with_mnemonic (label);
          image = gtk_image_new_from_stock (stock_id, GTK_ICON_SIZE_BUTTON);
          gtk_button_set_image (button, image);

    - e_create_directory() / e_util_mkdir_hier()

        Replace with g_mkdir_with_parents().


A side-effect of this cleanup effort is that I was able to pin down the
remaining deprecated widgets and functions that Evolution is still using.
Migrating away from them will be more involved than the cases addressed by
this bug, so I plan on dealing with each of them on a case-by-case basis.

Here's a list of the major deprecated items that Evolution is still using:

    gnome-config                (migrate to GKeyFile)
    GnomeDialog                 (migrate to GtkDialog)
    GnomeDruid                  (migrate to GtkAssistant)
    GnomeIconList               (migrate to GtkIconView)
    GtkCombo                    (migrate to GtkComboBoxEntry)
    GtkOptionMenu               (migrate to GtkComboBox)
    The old GTK+ object system  (migrate to libgobject)