TABQA-7431: upgrade product-upgradability-testing-utils to get support of TK management feature

git-svn-id: http://svn.terracotta.org/svn/ehcache@9083 b9324663-ca0f-0410-8574-be9b3887307d
TABQA-7431: fix NPE in register() + add generics to ResponseEntityV2

git-svn-id: http://svn.terracotta.org/svn/ehcache@9084 b9324663-ca0f-0410-8574-be9b3887307d