wp-admin post-screen: Make metabox visibility filterable

[pampfelimetten]

We are using wp as a cms and we want to influence the visibility options our users see. Right now, that part is hardcoded in wp-admin/includes/meta-boxes.php. We would appreciate a filter to influence the visibility options. I'd be willing to provide a patch, if I get a positive feedback from a core dev.

[helenyhou]

Related/duplicate: #12706, #12567

[DrewAPicture]

I think this qualifies as a dupe of #12567, closing.