Make the URL output in `_thickbox_path_admin_subfolder()` use `includes_url()`.

Props voldemortensen.
Fixes #14157.

Built from https://develop.svn.wordpress.org/trunk@29741


git-svn-id: http://core.svn.wordpress.org/trunk@29515 1a063a9b-81f0-0310-95a4-ce76da25c4cd
`WP_oEmbed::_strip_newlines` is called as a filter callback for `oembed_dataparse`, must be public. It was marked as private for fun in [14109] and then made `private` officially in [28507].

Fixes #29647 for trunk.


Built from https://develop.svn.wordpress.org/trunk@29742


git-svn-id: http://core.svn.wordpress.org/trunk@29516 1a063a9b-81f0-0310-95a4-ce76da25c4cd