Previously they did not always work correctly (and were not always consistent with each other), depending on the combination of choices that were
made on the form. This commit should fix those issues, and also adds two helper functions that make it easy to correctly add new AJAX-enabled
elements to this dynamic form.

Tests for the dynamic appearance of the "tagged with" form element on the wizard, to make sure it doesn't break again :)

Fix the ability of the "tagged with" field to dynamically appear and disappear on the wizard as appropriate, and update the tests.

Make all settings on the add new view wizard actually work, and store data in the correct displays (default or overridden, as appropriate). Also
add lots of tests.

Fix the dropdown for overriding displays, and a test for it. Also clean up several other issues in the tests.