[openstreetmap-website] Update to iD v1.8.0 (#1081)

[Tom Hughes]

Disabling the `cleanupIDs` plugin fixes it, but currently there is no way to do that via the `image_optim` gem that we use, hence my PR for it.

---
Reply to this email directly or view it on GitHub:
https://github.com/openstreetmap/openstreetmap-website/pull/1081#issuecomment-155098324
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/rails-dev/attachments/20151109/f7aa1dbd/attachment.html>