(bug 45142) dirty RTL CSS hack for Opera

For some absolutely inexplicable reason Opera confuses right and left
padding on li#pt-uls a.uls-trigger in RTL mode, causing the text to
overlap an icon. Use a CSS hack to flip the text direction for Opera
only.

Change-Id: I71c2c4cac3269551722b15c533a2d511e1b483d9
Merge "(bug 45142) dirty RTL CSS hack for Opera"