Inline documentation for hooks in wp-admin/includes/update-core.php.

Props JoshuaAbenazer, kpdesign.
Fixes #25998.


git-svn-id: https://develop.svn.wordpress.org/trunk@27047 602fd350-edb4-49c9-b593-d223f7449a82
Inline documentation for hooks in wp-admin/includes/export.php.

Props cmmarslender, kpdesign.
Fixes #26894.


git-svn-id: https://develop.svn.wordpress.org/trunk@27048 602fd350-edb4-49c9-b593-d223f7449a82