Code review comment for lp:~ursinha/launchpad/bug-391569-add-last-changed-column

= Summary =

https://bugs.edge.launchpad.net/rosetta/+bug/391569

This branch adds a "Last Changed" date in +translations pages, showing
the last date a translation in a given language was touched.

== Proposed fix ==

Added a last_changed_date property to the productserieslanguages interface, and changed
productserieslanguage to also return the last date changed among all POFiles
in a product, of a language.

== Pre-implementation notes ==

Discussed with Danilo.

== Tests ==

This should work:
  bin/test -vvt lp.translations.*

(but I did a full test run just to be sure :)

== Demo and Q/A ==

To check the changed pages, go to:
 - https://translations.launchpad.dev/evolution/trunk/+translations
 - https://translations.launchpad.dev/alsa-utils/trunk

= Launchpad lint =

Checking for conflicts. and issues in doctests and templates.
Running jslint, xmllint, pyflakes, and pylint.
Using normal rules.

Linting changed files:
  lib/lp/registry/model/productseries.py
  lib/lp/translations/interfaces/productserieslanguage.py
  lib/lp/translations/tests/test_productserieslanguage.py
  lib/lp/translations/templates/productseries-translations-languages.pt
  lib/lp/translations/model/productserieslanguage.py

== Pylint notices ==

lib/lp/translations/interfaces/productserieslanguage.py
    6: [F0401] Unable to import 'lazr.restful.fields' (No module named restful)