layout: Substitute and improve RTL flipping
layout: Substitute and improve RTL flipping

Follows-up f60db75, which fixed some of the inintended automatic
flipping when loading the Beta version from mediawiki.org.

This commit substitutes the remaining rules that we want to have
flipped in RTL. That way it will work in the stable version as well.

Fixes #65.

Krinkle/mw-gadget-rtrc