"Ready for Publication" button needed for contributing authors

[skippy]

Contributing authors, who cannot directly publish items, need a way to communicate to editors that a draft is ready for publication.

There should exist on the Write screen a button that provides this facility. A "Ready for Publication" button should:

• notify editors by email that a new post draft is ready for final review / publication
• add the draft to a new list at the top of the Manage screen -- above the "Other's Drafts" section.

It might be nice to allow editors to accept OR reject the draft, along with a reason, but that bit might be better handled by a plugin.

This is basically a duplicate of ticket #2238 : "Roles: Notification of posts to be published"