[DS-1834] Collection content source harvesting test does not check sets properly

Had to change the way that sets are checked since the "ListSets" class does not support a constructor with a resumption token.
We may need to alter this code again once a new version of the "oclc-harvester2" is released. The latest version of the ListSets class does support the resumptionToken (http://oaiharvester2.googlecode.com/svn/trunk/src/ORG/oclc/oai/harvester2/verb/ListSets.java), but has not been released.