Code review comment for lp:~deryck/launchpad/fix-subscriber-windmill-fragility-497112

This branch attempts to fix the bug subscribing Windmill test failure
reported in bug 497112. I say *attempts* because the error only happens
when running the entire Windmill suite and hasn't happened since I
recorded the bug. I can't reproduce this failure.

However, this section of the test could be made less fragile by relying
on IDs rather than xpath to find elements.

So this branch creates an id for direct subscribers and makes the test
use IDs for the direct and dupe subscriber part of the subscribe someone
else section of the test (which was the part that failed).

To test:

./bin/test --layer=BugsWindmillLayer -vvt test_bug_inline_subscriber

A couple of additional notes:

1) I focused only on the reported failure area, and I am working on a
branch to clean up the test generally to use these IDs.

2) the official-bug-tags js script is reporting lint errors, which is an
unrelated bit of the code. I have fixed this in a separate drive-by
branch and will put that up for review shortly.

= 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/bugs/templates/bug-portlet-subscribers-content.pt
  lib/canonical/launchpad/javascript/bugs/bugtask-index.js
  lib/lp/bugs/windmill/tests/test_bug_inline_subscriber.py