Add back CSS rules for RTL resize handles.

Disable CSSJanus' swapLtrRtlInUrl option, as we currently don't use it otherwise (and it breaks this if left on).

props ocean90.
fixes #26449.


git-svn-id: https://develop.svn.wordpress.org/trunk@26731 602fd350-edb4-49c9-b593-d223f7449a82