HSEARCH-1571 Upgrade to Infinispan 7.0.0.Alpha2
HSEARCH-1527 Upgrading to Lucene 4.7

Refactoring DistanceComparator to not make use of IntToDoubleMap which does not exist anymore
HSEARCH-1527 Updating POM name and description of infinispan module.
HSEARCH-1570 Redundant version definition in the infinispan module
HSEARCH-1572 SerializationHelper not closing object streams
HSEARCH-1508 Tune IndexWriter options to allow for highly concurrent usage