Creates treeview columns, and connect missing signals

def register_view(self, view):
        """Creates treeview columns, and connect missing signals"""
        cb = self.view['cb_currency']
        cb.set_model(self.model.currencies)
        cell = gtk.CellRendererText()
        cb.pack_start(cell, True)
        
        def on_cell_data(cb, cell, mod, it):
            if mod[it][0]: cell.set_property('text', mod[it][0].name)
            return

        cb.set_cell_data_func(cell, on_cell_data)
        return