OO-3108: close the file system created for zip files, set default encoding to UTF-8 for some stream to string operations

OO-1443: upgrade JUnit ( long overdue ), remove deprecated junit.* packages, fix some issues with order dependent tests, fix an issue with empty ClusterDoInSync

OO-990: fix a case where the SCORM package is not detected if the manifest files is at the root level and a single folder contains the SCOs