unable to set work in progress via email

[John A Meinel]

slightly related to bug #397444 but more from a reviewer's perspective.

At the moment via the web interface a merge proposal status can be set to:
  work in progress
  needs review
  approved
  rejected
  merged

However, the email api seems to only allow:
  merge approved
  merge rejected

And no way to set the other statuses. (At least, when I tried "workinprogress" it told me that valid values are "accepted" and "rejected".)

It would be nice to be able to do a review just via email, and say that "this needs fixing, and kick it out of the review queue until it has been done." And I imagine that the person fixing it would like to be able to say "I've done the work, could you review this again". Which would be a case for WIP and NR. I don't see a particular reason why Merged wouldn't be allowed via email either...