[openstreetmap-website] Obtain changeset comment for /api/[node|way|relation](/history) (#584)

[Simon Legner]

A pull request for #534.

Adds attribute `changeset_comment` to `<node>`/`<way>`/`<relation>` for `/api/0.6/[node|way|relation]/#id` and `/api/0.6/[node|way|relation]/#id/history`.
You can merge this Pull Request by running:

  git pull https://github.com/simon04/openstreetmap-website changeset_comment

Or you can view, comment on it, or merge it online at:

  https://github.com/openstreetmap/openstreetmap-website/pull/584

-- Commit Summary --

  * API: de-duplicate metadata code for n/w/r
  * API: extract changeset_comment for node/way/rel

-- File Changes --

    M app/models/node.rb (50)
    M app/models/old_node.rb (29)
    M app/models/old_relation.rb (28)
    M app/models/old_way.rb (28)
    M app/models/relation.rb (26)
    M app/models/way.rb (26)

-- Patch Links --

https://github.com/openstreetmap/openstreetmap-website/pull/584.patch
https://github.com/openstreetmap/openstreetmap-website/pull/584.diff
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/rails-dev/attachments/20131201/dd761adc/attachment-0001.html>