Preview: Update to Hibernate Search 5.0

This is a preview for the changes which will be needed to upgrade to HS5.
I still need to release the new HQL Parser, will do that when I'll have resolved one last problem with the hot rod integration - but tests with OGM are fully passing now.

What needs to be discussed: how to isolate the Neo4J / Lucene 3 dependency?
It currently fails the dependency convergence tests.