Force LTR direction for code and plugin/theme editors.

Merges [26888] to the 3.8 branch.

props SergeyBiryukov, nivijah.
fixes #26666.


git-svn-id: https://develop.svn.wordpress.org/branches/3.8@26954 602fd350-edb4-49c9-b593-d223f7449a82
Change 'Width' to 'Layout' to match the hard-coded list of translatable theme features in get_theme_feature_list().

Merges [26905] to the 3.8 branch.

props janrenn.
fixes #26777.


git-svn-id: https://develop.svn.wordpress.org/branches/3.8@26955 602fd350-edb4-49c9-b593-d223f7449a82
Keyboard navigation friendliness for themes.php.

Merges [26922] to the 3.8 branch.

props matveb, azaozz, jorbin.
fixes #26527.


git-svn-id: https://develop.svn.wordpress.org/branches/3.8@26956 602fd350-edb4-49c9-b593-d223f7449a82
Themes: Search the theme's slug too.

Merges [26921] to the 3.8 branch.

props matveb.
see #26730.


git-svn-id: https://develop.svn.wordpress.org/branches/3.8@26957 602fd350-edb4-49c9-b593-d223f7449a82