Revert "split IndexManager into StartUp and Shutdown, make tests compile but not working yet"

This reverts commit 05288563ecb8d172fc4ca9cc8842d08ac82e5367.
exclude REST client integration test in surefire/pom, but leave it
active for testing locally
rename integration tests to *IntegrationTest and exclude from normal
test run
make factory methods in Index resource private and use Mockito Whitebox
facility to set the mock instead of inject
split IndexManager again into ES (cluster state), make tests compile but
not working yet
remove IndexManagerCoreException, not needed and subclasses do not need
to be declared
move back parts of ES (cluster state) into IndexManager
fix StackOverflow
drop JPADataAccessLayer and inject entityManager directly into Dao
use Mockito Whitebox facility to set the injected resources for
integration tests
extract common setup for Derby database and create extra JUnit rule for
that
remove unused import
rename IndexManagerDao to its real name RunningIndexConfigDao, remove
Transaction Template and use annotation/interceptor transaction.
add UserID Json serializer
move Transaction interfaces into JPA package, this is JPA specific and
only technical