[pygtk] Add a combo button

[saeed]

Yes, if you will have only a text for any combobox item(and don't need
image beside text for example), the more simple way is to use:
gtk.combo_box_new_text()
But you can have many columns in a combobox(like a treeview)
containing anything that is supported by CellRenderer (for example
text, Pixbuf, SpinButoon, CheckButton and ProgressBar!).
See here for more details
www.pygtk.org/pygtk2tutorial/sec-ComboBoxAndComboboxEntry.html