[giow] (1) Move all requirements about bidi out and just rely on CSS instead. Also, fix the CSS rules for <bdo>. Follow-up changes for W3C HTML5 CR bug 22326.

Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=23260
Affected topics: HTML, Rendering

git-svn-id: http://svn.whatwg.org/webapps@8317 340c8d12-0b0e-0410-8428-c7bf67bfef74
(cherry picked from commit f397c78de13607ff21d27e112e4663447672a409)
(cherry picked from commit 36b26490d39317e1ad47df1ae14e9fe63b32c2dd)
[e] (0) Clarify bidi CSS rules interaction
Affected topics: Rendering

git-svn-id: http://svn.whatwg.org/webapps@8332 340c8d12-0b0e-0410-8428-c7bf67bfef74
(cherry picked from commit 14f80c82877e0c61187d8af8aa1c9d4738294466)
(cherry picked from commit 734a214dfdee242d3ce37d78b4a3bd94efd9630f)