title: couchdb, how to rename an attachment
body: <p>I'm writing cms like application and I would like my images to be stored as attachments in couchdb. 
  The problem is in naming the attachments because I don't want my images to be named the same (e.g. /db/doc_id/thumb.jpg)</p>
  
  <p>Ideally attachments names should depend on doc.name field. To make this work I would have to rename attachment each time user changed the name (description|alt) of current photo document.</p>
  
  <p>So my question is: how to change attachment name? or maybe I should go other way in solving my problem?</p>