TaxonomyVocabularyTestCase assumes auto-increment increment of 1

This test explicitly requires knowledge of an ID to be assigned in the future by auto-increment. The test tries to load a non-existent vocabulary by vid (ensuring ti fails), then creates the vocabulary, then ensures it can load the vocabulary by vid. In order for this test to pass when the auto-increment increment is not 1, the increment must be known. This could be accomplished by detecting the increment (https://drupal.org/node/549662) or by extending the database drivers to report the increment.