Fix shelf numbering
Fix shelf numbering

id must be unique. So if we have 2 zones with 1 shelf in each, hide 1
zone and add a new shelf, it must get id "hidden shelf" + 1

git-svn-id: 6ac5796aeae0cef97fb47bcc287d4ce899c6fa6e@45563 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33

jordemort/e17,jordemort/e17,jordemort/e17