Workflow: Editor should be able to edit document without having to Reject a request first

Some end user feedback from Niels van Kampenhout:
"Another irritation for the end-users is their inability to edit a document that is pending approval. There's a 3- or 4-step process where they have to reject the publication request before they can edit/save, then resubmit. Those are a lot of steps to do since Hippo 6 doesn't have those kinds of constraints."

"The use case is: an editor wants to edit a document before accepting a publication request for this document. In Hippo 6, they could directly hit edit and make the change, then publish. In Hippo 7, the edit action is not allowed if there is an outstanding publication request. So what they do is reject the request to be able to edit the document. And then publish it directly I guess. I think it would make sense that an editor can edit a document before accepting a publication request. After all that's what an editor is supposed to do: edit the content that the authors submit."