Fixed deprecated warnings with python3-gobject 3.13.3.

python3-gobject adds several warnings in gi/overrides/Gtk.py

/usr/share/ibus-anthy/setup/main.py:1519: PyGTKDeprecationWarning:
The "buttons" argument must be a Gtk.ButtonsType enum value. Please
use the "add_buttons" method for adding buttons.
See: https://wiki.gnome.org/PyGObject/InitializerDeprecations

/usr/lib64/python3.4/site-packages/gi/overrides/Gtk.py:537:
PyGTKDeprecationWarning: The keyword(s) "parent" have been deprecated
in favor of "transient_for" respectively.
See: https://wiki.gnome.org/PyGObject/InitializerDeprecations
Set max-width-chars property in ibus-anthy-setup wrapped GtkLabel.
Set a parent window from 'IBUS_SETUP_XID' environment variable in setup.
Added another status icon for input mode.
Updated translations.
Fix to unref pixbuf when propery icon is unrefed.
Fix None object has clear() in input mode icon. (#1097364)