Removing some internal generics, SearchFactory lookup improvement

.. and Hibernate ORM upgrade.

The changes around generics are meant to remove "noise" from upcoming patches coming from the camp of free form entities indexing.

 - https://hibernate.atlassian.net/browse/HSEARCH-1629
 - https://hibernate.atlassian.net/browse/HSEARCH-1632
 - https://hibernate.atlassian.net/browse/HSEARCH-1633