Use Hibernate Search Kit compatible with AS 7.2

The current version of Hibernate Search (4.2) provides a kit which is only compatible with AS 7.1, it is not compatible with AS 7.2.

There are at least the following incompatibilities:

1) the module structure is different (AS 7.2 uses modules/system/layers/base as root)
2) the problem described here: https://community.jboss.org/message/742694 (in short, for AS7.2 HSearch needs an explicit dependency on the org.hibernate.commons-annotations module which has been split from the standard org.hibernate)
3) infinispan-lucene-directory is not present in the kit (causes a java.lang.NoClassDefFoundError: org/infinispan/lucene/InfinispanDirectory )

Because of the above, we've had to change our build system (specifically the pom.xml from the distribution module and the as72 assembly descriptor) to work around these issues.

When Hibernate Search will provide a 7.2 compatible kit, we should use that and cleanup our code.