Differences between Search 4.4.x and the "JDG compatible edition"

@hferentschik @emmanuelbernard 
Sending a fake PR to myself here to allow you to comment on the patches which are going to be needed to build the "special edition", built on top of the PR I've sent to
https://github.com/hibernate/hibernate-search/pull/680

This should allow us to cut a release from 4.4 for inclusion into EAP and keep the changes to this minimal set; inclusion into EAP goes via jars and wouldn't be affected by these changes so we can satisfy the "same binaries" rule.