Handle zero vectors in MathUtils.cos method (#1676)
Prevent NPE in Trust PostUpdateEventUserListener
Add ITrustRepository.retrieveCssBySimilarity method (#1676)
Add ITrustRepository.retrieveMeanTrustValue method (#1676)
Add IIndirectTrustEngine interface to TME internal API (#1676)
Initialise trust similarity to zero (#1676)

* Improve TrustedEntity.toString and Trust.toString methods
Improve Trust Similarity Evaluator to express exactly opposite trust
preferences (#1676)
Integrate Indirect Trust Engine with Trust Similarity Evaluator (#1676)