Add setting to skip migrations when building test db

We periodically add data via data migrations. However with test-utils,
the first time you run tests that depend on that new data, they work but
subsequent tests will fail.

However, this is the same situation we had with schematic. We use model
makers to generate data we need for tests.

Ergo, there's no reason to run the south migrations to create the test
db.

This shuts that off.
[bug 934558] Enable Finnish support forum.
Fix generatedata

* the hacking howto has instructions for creating the db that don't
  include setting the CHARSET so it would die on creating revisions
  using the revision model maker which includes unicode data
* the revision model maker code value strings were ... "interesting"
* cosmetic: i tweaked the formatting in the MozillaNews.wiki
Undo tweaking MozillaNews.wiki since it's going away.
[bug 915688] Fix for tablets. Now they  are not MOBILE.
[bug 933930] Update django-badger to c04372a.
[bug 935498] Remove Mozilla News section.
[bug 932645] First approved revision is of MAJOR_SIGNIFICANCE.
[bug 920922] Remove sr-Latn locale.

* Moves sr-Latn user profiles to sr-Cyrl
* Deletes sr-Latn documents
* Deletes sr-Latn locale team
* Deletes sr-Latn images and videos
* Deletes sr-Latn wiki metrics
[bug 673947] Use display name on discussion forums
[bug 932348] Escalate questions to zendesk when tagged "escalate".
[bug 937183] @require_POST for logout view.
[Bug 915686] Rickshaw: Add toggles to mini legends.
[bug 933474] FF download button warning message
[bug 940311] Check if updated_by is set before using.
Undo accidental django-badger downgrade.