Twenty Thirteen: first pass at better color contrast for links. Also fixes very poor contrast for h3-h6 headings in footer widget area. Props jorbin and sabreuse. See #23513

git-svn-id: http://core.svn.wordpress.org/trunk@23514 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix internal linking dialog conflicts with jQuery UI 1.10.x. Syncs jQuery UI CSS styles.

Remaining issue will be fixed in 1.10.2 final.
props ocean90.
see #23370.



git-svn-id: http://core.svn.wordpress.org/trunk@23515 1a063a9b-81f0-0310-95a4-ce76da25c4cd