Twenty Thirteen: minor design tweaks and fixes:

 * Link color should be the same on all links that are on white or tan backgrounds, see #23784
 * Better color value for active menu item (red instead of tan)
 * Improved styles for quote citations that are wrapped in links
 * Better layout for single post navigation links when post titles are '''really''' long
 * Fix navbar border style for viewports at 1600 pixels wide and above

Props Joen and obenland.

git-svn-id: http://core.svn.wordpress.org/trunk@23962 1a063a9b-81f0-0310-95a4-ce76da25c4cd