MODE-2066 Migrated to Infinispan 6.0.1 and JGroups 3.4.1. 

* beside the changes involving package migrations and API changes, because the BDB and JDBM cachestore have not been ported to 6.x yet, all references (only unit tests) to those cache stores were removed and replaced with `LevelDB`. 
* ModeShape never worked with ~~JdbcBinaryStore~~ `JdbcBinaryCacheStore` and therefore any tests which used this type of store were removed.
* the old `FileCacheStore` has been discontinued and therefore replaced with `SingleFileStore`.
* unused (but present in the classpath) `hibernate-search-infinispan` dependency was removed altogether because it is not compatible with ISPN 6.x.
* the AS7/EAP integration tests have been disabled temporarily until the kit is ported to Wildfly.

This pull request superseeds https://github.com/ModeShape/modeshape/pull/1041 which should be closed.