Make nav menu item add tabs and content consistent with similar tabs on the post edit screen. props corvannoorloos for the initial patch. fixes #26757.

Built from https://develop.svn.wordpress.org/trunk@27229


git-svn-id: http://core.svn.wordpress.org/trunk@27086 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove unnecessary assignment and concatenation from the_date() and get_the_date().

props juliobox.
fixes #27181.
Built from https://develop.svn.wordpress.org/trunk@27230


git-svn-id: http://core.svn.wordpress.org/trunk@27087 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Correct @return value for get_the_date().

props TobiasBg.
fixes #27181.
Built from https://develop.svn.wordpress.org/trunk@27231


git-svn-id: http://core.svn.wordpress.org/trunk@27088 1a063a9b-81f0-0310-95a4-ce76da25c4cd