[development] save as draft feature

[justin randell]

hi all,

i'm after feedback on exactly what a "save revision as draft"[1]
feature should look like in drupal.

here are some initial thoughts:

1. make it be possible to save an existing node or revision as a draft
by adding a save as draft button
- if there is already a draft associated with the node, copy over it

2. make it possible to 'promote' an existing revision to a draft from
the 'revisions' tab
- if there is already a draft associated with the node, copy over it

3. drafts can be deleted, which sets the node draft column to 0 and
deletes the revision

4. drafts can be updated without creating new revisions

5. changes to the published/unpublished status of a draft's 'parent'
node has no effect on a draft's status

5. add a draft id column to the node table - one draft per node. the
value in this column would correspond to the vid of the row in the
node_revisions table for the draft. a value of 0 would represent 'no
draft' for a node

6. add a 'draft' tab to the node view, alongside the 'view' and 'edit' tabs

7. add some draft node permissions, so a user can be allowed to edit a
node's draft without effecting live content

i'm not aiming for a full workflow, just to allow for basic draft functionality.

ideas, comments, etc all welcome.

cheers
justin