Introduce configuration property for defining jpa provider version

[beikov]

Since a fat jar deployment would make version detection impossible to some extents as has been discussed in #258, we should add a property which can be used to configure the jpa provider implementation version.

[beikov]

You can now put an implementation of HibernateVersionProvider on your classpath which provides the version via a method. This should do the trick for fat jar deployments. @jwgmeligmeyling

[jwgmeligmeyling]

Great! I'd been working on other pieces of my code as the minor Hibernate 5.2.3.Final release introduced breaking changes with setting native query parameters (they switched from 0 to 1 as start index). Pretty annoying, so I didn't have a chance to look into this issue more :)