Return post data from post delete endpoint - #627

Anyone disagree with this one? Could theoretically interfere with a custom status of deleted. We could alternatively indicate this some other way.

gone :)

delete would closer fit the existing naming pattern for statuses.

My other thought was using null, or setting the ID to null. These don't interfere with custom statuses at all, which is nice, but setting the value to null might drop some clients back to default handling for the field (we say to treat it as a draft if you don't get/understand the field), while changing the ID seems like it's removing important information.