Twenty Fourteen: RTL fixes for the navigation.

props yoavf.
fixes #26200.

Built from https://develop.svn.wordpress.org/trunk@26796


git-svn-id: http://core.svn.wordpress.org/trunk@26683 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Move pointer-specific CSS from wp-admin.css to wp-pointer.css.

props ocean90.
fixes #26477.

Built from https://develop.svn.wordpress.org/trunk@26797


git-svn-id: http://core.svn.wordpress.org/trunk@26684 1a063a9b-81f0-0310-95a4-ce76da25c4cd