In media_upload_flash_bypass(), pass the post id in the media-new.php url.

In media-new.php, use post_id from REQUEST if passed and the current user can edit the post.
Fixes adding media with the browser uploader.

Props nacin, ocean90
fixes #22572


git-svn-id: https://core.svn.wordpress.org/trunk@22853 1a063a9b-81f0-0310-95a4-ce76da25c4cd