Prepare migration to Spring 4

This issue is technically. To move to Spring 4, we need to remove the AbstractOLATModule + PersistedProperties construct in XML configuration.
It's a follow-up of OO-1527

• Fix LDAP beans dependency loop ( which cause failed startup on faculty recruiting tool )
• Break the cycle SearchService <-> JmsIndexer ( it only needs to know if the indexer is enabled on the instance )