Don't show the Featured Image metabox for users with the `contributor` role. Do enqueue media so that TinyMCE previews work for YouTube embeds, etc.

Props SergeyBiryukov.
Fixes #28327.

Built from https://develop.svn.wordpress.org/trunk@29402


git-svn-id: http://core.svn.wordpress.org/trunk@29180 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In `media.view.BulkSelectionActionButton.click()`, do not assume that `delete` is the only possible bulk action.

Fixes #29101.

Built from https://develop.svn.wordpress.org/trunk@29403


git-svn-id: http://core.svn.wordpress.org/trunk@29181 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Ignore entities in XML-RPC requests.

props mdawaffe, nacin.

Built from https://develop.svn.wordpress.org/trunk@29404


git-svn-id: http://core.svn.wordpress.org/trunk@29182 1a063a9b-81f0-0310-95a4-ce76da25c4cd