cleanup, and additional function for binary tests

In addition, I've removed the addition of a new user with different permissions being performed every time and created a new test in islandora_solution_pack_collection called islandora_basic_collection_usage_permissions.test; this test runs through each step of an object ingest and purge, creating a new user in each step. Segregating this test so that we only do it once should make the other tests run faster and cleaner.