Twenty Fifteen: beautify the header in IE 8.

Props afercia, fixes #30042.


Built from https://develop.svn.wordpress.org/trunk@29972


git-svn-id: http://core.svn.wordpress.org/trunk@29718 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fifteen: correct button sizes.

Props iamtakashi, fixes #30045.


Built from https://develop.svn.wordpress.org/trunk@29973


git-svn-id: http://core.svn.wordpress.org/trunk@29719 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fifteen: correct comment meta alignment when avatar display is turned off.

Props iamtakashi, fixes #30046.


Built from https://develop.svn.wordpress.org/trunk@29974


git-svn-id: http://core.svn.wordpress.org/trunk@29720 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fifteen: Adding in the twentyfifteen credits action.

Props iamtakashi, fixes #30051.


Built from https://develop.svn.wordpress.org/trunk@29975


git-svn-id: http://core.svn.wordpress.org/trunk@29721 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fifteen: updated styles for skip link.

Props afercia and iamtakashi, fixes #30043.


Built from https://develop.svn.wordpress.org/trunk@29976


git-svn-id: http://core.svn.wordpress.org/trunk@29722 1a063a9b-81f0-0310-95a4-ce76da25c4cd