Use new $args parameter for (WP_Rewrite::)add_permastruct(). Fixes #16092.

Use array_intersect_key() to keep WP_Rewrite::$extra_permastructs free of unnecessary/unknown keys + values.


git-svn-id: https://core.svn.wordpress.org/trunk@19779 1a063a9b-81f0-0310-95a4-ce76da25c4cd