Added tests for the comparators.

FYI (with cobertura):

AbstractResource (50%)
AdmissionResultComparator (80%)
AdmissionResultPerCandidateResource (0%)
AdmissionResultsProcessor (93%)
AdmissionResultsResource (0%)
CandidateComparator (66%)
CandidateResource (0%)
CandidatesResource (36%)
DaoHolder (80%)
MainApplication (100%)
ResultsPDFExport (0%)