Introduced `dayofweek_iso` time param for `WP_Date_Query`.

The initial `dayofweek` param sets day 1 to Sunday. This is out of step with
ISO standards, which calls Monday day 1. To maintain backward compatibility
with the existing parameter, we introduce the new `dayofweek_iso` for the
new, more compliant param.

Props mboynes.
Fixes #28063.

git-svn-id: https://develop.svn.wordpress.org/trunk@30142 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: Make featured content in Customizer contextual to the front page.

Props celloexpressions, fixes #29578.


git-svn-id: https://develop.svn.wordpress.org/trunk@30143 602fd350-edb4-49c9-b593-d223f7449a82
Improve default argument formatting in `WP_Date_Query::__construct()`.

git-svn-id: https://develop.svn.wordpress.org/trunk@30144 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Ten and Eleven: don't display modified excerpt link in wp-admin.

Props kraftbj, fixes #30026.


git-svn-id: https://develop.svn.wordpress.org/trunk@30145 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: fix keyboard focus on Appearance > Header view.

Props florianziegler, fixes #29787.


git-svn-id: https://develop.svn.wordpress.org/trunk@30146 602fd350-edb4-49c9-b593-d223f7449a82