[ubuntu-art] Expansor widget or arrows themes in Ubuntu theme.

[Josué Alcalde González]

Why the "expansor widget" is not customized in most of themes and
shouldn't it be customized in Ubuntu theme.

I suggested using a theme very similar to checkbox, whit a grey border
and an orange colour to fill it when focus.

Other idea, a focus border like buttons and textfields and the orange
colour when expanded.