RTL support in hippo canvas

["Marco Pesenti Gritti" <mpgritti gmail com>]

Hello,

we have a few hippo canvas views in Sugar where we would need to
support RTL layout. We have patches to manually reverse various boxes
depending on the gtk RTL flag. I was wondering if we could come up
with a better way to solve this in hippo...

I can think of a couple of possibilities:

* Automatic swapping a la gtk.HBox. I'm worried we might hit two many
"false positives". Dan Winship experimented with this approach a while
ago and I think he run into issues.
* Support a direction:auto/rtl/ltr property in the stylesheets (auto
would depend on the gtk rtl flag).

What do you think? Better ideas?

Thanks,
Marco