Automatically setup shared indexes when indexing is enabled

• on replicated Caches, we should create a default index on a FSDirectory and provide some appropriate default tuning, for example enabling NRT.
• distributed Caches will need the Infinispan Directory (shared) and a master/slave backend (Infinispan IndexManager, while NRT is not compatible in this case)

We want to keep the properties configuration structure as well as an "advanced tuning" and override capabilities of the default choices.
Some more common options like sync/async indexing should probably be promoted to be controlled by the XML elements and configuration DSL excplicitly.