Follow-on to 949b8cda14ec037386da34c43248ebd60542f5da for #1982.
- Add extra condition to Item_Model_Test::urls_test to test cache busters of missing files.
- Previous commit fixes unit test for empty album url, but now no test checks missing files.
Merge pull request #122 from shadlaws/followon_1982_part_2

Follow-on to 949b8cda14ec037386da34c43248ebd60542f5da for #1982.