Code review comment for lp:~sinzui/launchpad/edit-question-bug-210312

This is my branch to fix some simple issues with Launchpad Answers.

    lp:~sinzui/launchpad/edit-question-bug-210312
    Diff size: 334
    Launchpad bug: https://bugs.launchpad.net/bugs/210312
                   https://bugs.launchpad.net/bugs/275475
                   https://bugs.launchpad.net/bugs/386158
    Test command: ./bin/test -vv \
        -t answers.*views.txt
        -t question-subscriptions
        -t this-is-a-faq
    Pre-implementation: no one
    Target release: 3.1.12

= Fix some simple issues with Launchpad Answers =

Bug 210312 [cannot edit the language of the question]
    The question +edit page only shows the user's preferred languages. It
    must show all languages so that the user can fix the language.

Bug 275475 [launchpad displays the hint for subscribing when i click on
    unsubscribe]
    The paragraph talks about subscribing, but the action is unsubscribing.

Bug 386158 [confusingly redundant fields in create faq page]
    There are two textareas, each of which seems to want the answer to the faq.

== Rules ==

Bug 210312 [cannot edit the language of the question]
    * Remove the QuestionSupportLanguageMixin and use the interface's
      language

Bug 275475 [launchpad displays the hint for subscribing when i click on
    unsubscribe]
    * Add a condition to the template to select the right paragraph to show.

Bug 386158 [confusingly redundant fields in create faq page]
    * Revise the field labels and hints to distinguish between the FAQ and
      the question the user is answering.

== QA ==

Bug 210312 [cannot edit the language of the question]
    * Edit a question on edge.
    * Verify the language choice contains every language registered in
      Launchpad.

Bug 275475 [launchpad displays the hint for subscribing when i click on
    unsubscribe]
    * Choose the subscribe link on a a question.
    * Verify the link to your subscriptions page actually goes to your
      subscription page.
    * Choose the Subscribe button
    * Choose the Unsubscribe link
    * Verify that the paragraph talks about the consequence of unsubscribing.

Bug 386158 [confusingly redundant fields in create faq page]
    * Choose create a new FAQ link from any question.
    * Verify the FAQ field speak of "this FAQ".
    * Verify the last field labeled "Additional comment for question #..."

== Lint ==

Linting changed files:
  lib/lp/answers/browser/question.py
  lib/lp/answers/browser/tests/views.txt
  lib/lp/answers/interfaces/faq.py
  lib/lp/answers/interfaces/question.py
  lib/lp/answers/stories/question-subscriptions.txt
  lib/lp/answers/stories/this-is-a-faq.txt
  lib/lp/answers/templates/question-subscription.pt

== Test ==

    * lib/lp/answers/browser/tests/views.txt
      * Modernised part of the test--they predated LaunchpadFormView
      * Added label and page_title tests to verify that sane fragments
        for subscribe/unsubscribe were created for the automated rules.
      * Verified that the QuestionEdit form uses the LanguageVocabulary.
    * lib/lp/answers/stories/question-subscriptions.txt
      * Removed some cruft from the story.
      * Revised the story to verify the links in the subscribe page and
        the paragraph for the unsubscribe page.
    * lib/lp/answers/stories/this-is-a-faq.txt
      * Added a test to verify that the question message field has a
        very clear label (created by the view).

== Implementation ==

    * lib/lp/answers/browser/question.py
      * Removed the redundant question number form the page_title and
        breadcrumbs. The automatic rules showed Question #12: Question #12
      * Fixed some spacing/wrapping issues reported by lint.
      * Added the IQuestion.language field, remove the
        QuestionSupportLanguageMixin language field.
      * Revised the rules to add the IQuestionLinkFAQForm['message'] field
        to the create FAQ form. It now creates a copy of the field and
        changes the title to 'Additional comment for question #12' to make
        if field's purpose clear when next to FAQ fields.
    * lib/lp/answers/interfaces/faq.py
      * Updated the descriptions of FAQ fields so that their context is clear
        when question fields are appended to them by views.
    * lib/lp/answers/interfaces/question.py
      * Updated the question message field description to clarify that the
        message is a question comment.
    * lib/lp/answers/templates/question-subscription.pt
      * Removed unused 1.0 heading.
      * Made the subscribe/unsubscribe paragraphs conditional.
      * Updated the link to person subscriptions to go to the actual
        subscriptions page.