Allow Phriction document edits to be saved as drafts
When a user edits a page normally, add a "Save as Draft" button. Much of this change is around making that button render and behave properly: it needs to be an <input type="submit" ...> so browsers submit it and we can figure out which button the user clicked.
Then there are a few minor rules:
- If you're editing a page which is already a draft, we only give you "Save as Draft". This makes edits to update/revise a draft more natural.
- Highlight "Publish" if it's a likely action that you might want to take.
Internally, there are two types of edits. Both types create a new version with the new content. However:
- A "content" edit sets the version shown on the live page to the newly-created version.
- A "draft" edit does not update the version shown on the live page.
Test Plan: Edited a published document, edited the draft. Published documents. Reverted documents.
Reviewed By: amckinley
Maniphest Tasks: T13077
Differential Revision: https://secure.phabricator.com/D19662