Add 'archive' button in production stage

[heike-r]

There are requests here and here for a possibility to archive a submission in production stage without declining or publishing it. Scenarios where this is neccessary:

1. A journal uses OJS only for management of peer review and layout editing, but not for actual publication. However, they want to keep the accept/decline statistics so declining is not an option after the whole production is finished. Submissions are now cluttering the 'active submissions' list.
2. A journal uses OJS for management but does import the final issue/galleys per native XML. To keep the review history, the original submissions are not overwritten but kept. Now, they are cluttering the 'active submissions' list, while the imported issues are published and moved to the archive.

Is this possible with the distinction as follows:

declined (due to peer review): status=4 and stage_id=3 archived (due to editorial management practise): status=4 and stage_id=4