Code review comment for lp:~bac/launchpad/bug-499351-batching-dls

= Summary =

For products with a large number of series or releases the +download page becomes too
big, loads slowly, and sometimes times out. There is too much information to be useful.

== Proposed fix ==

Batch the releases shown.

== Pre-implementation notes ==

Talked with Curtis.

== Implementation details ==

Create a class with a tuple of (series, release) and batch those.

For product administrators the links to all series and releases are maintained at the
bottom of each page.

== Tests ==

bin/test -vv -t product-files-views.txt -t xx-product-files.txt

== Demo and Q/A ==

Look at a big project like https://edge.launchpad.net/bzr/+download and see that the
batching works right.

= Launchpad lint =

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

Linting changed files:
  lib/canonical/config/schema-lazr.conf
  lib/lp/registry/browser/tests/product-files-views.txt
  lib/lp/registry/templates/product-files.pt
  lib/lp/registry/templates/productreleasefile-macros.pt
  lib/lp/registry/browser/product.py
  lib/lp/testing/factory.py
  lib/lp/registry/stories/product/xx-product-files.txt
  lib/lp/registry/browser/tests/test_views.py
  configs/development/launchpad-lazr.conf

== Pylint notices ==

lib/lp/registry/browser/product.py
    54: [F0401] Unable to import 'lazr.delegates' (No module named delegates)

lib/lp/testing/factory.py
    17: [F0401] Unable to import 'email.Encoders' (No module named Encoders)
    18: [F0401] Unable to import 'email.Utils' (No module named Utils)
    19: [F0401] Unable to import 'email.Message' (No module named Message)
    20: [F0401] Unable to import 'email.MIMEText' (No module named MIMEText)
    21: [F0401] Unable to import 'email.MIMEMultipart' (No module named MIMEMultipart)