Polish CS API revamp

Still some TODOs:

• 3.4 name consistently
• Make ClusterStore configuration match the name (ClusterLoader)
• 3.5 - move the params from init to an instance named InitializationContext that contains context info (is singleton etc, and also marshaller etc)
• 4 - push pull request
• 5 - remove all the "store" references from the code
• 6 - don't use "bulk" in the name of them methods ...
• 7 - make CacheLoaderException runtime
• 8 - rename EntryFactory in ContextEntryFactory and MVCCEntry in ContextEntry
• 9 - make StoreConfiguration aware of purging etc
• 10 - add removed test to the compatibility module: ConfigurationCompatibilityTest.testModeShapeStoreConfiguration
• - FileCacheStoreTest
• 11 - remove EHCache2InfinispanTransformerTest and other product migration tests in general + user manual entries
• 12 - Config: loaders/shared should be configured on a per cache basis.
• - action - lockAcquisitionTimeout (moved to bucket), concurrencyLevel (mode to bucket),
• purgerThreads & purgeSynchronously(removed as purging is async anyway)
• - purge on startup should be renamed to clean on startup as purging, as a term, is already used for cleaning
• up expired entries
• 13 - add test to show that notification happens for purged entries
• 14 - add interruption support in the code that invokes the CacheLoaderTask
• 15 - allow the number of map/reduce threads that iterate over the store to be configured
• 16 - Make ByteBuffer an interface and add a factory for it. Also consider adding a factory for MarshalledEntry
• 17 - rename org.infinispan.loader -> o.i.persistence
• 18 - remote gets should not serialize the entries but operate on bytebuffers directly
• 19 - make sure cachestore string is not present int he source base
• 20 - https://community.jboss.org/thread/232195
• 21 - remove DataManipulationHelper
• 22 - move Sleepycat Berkeley DB Java Edition license to the right place
• 23 removed 5.2 and 5.3 config files from the test resource dir
• 24 make the name consistent in the other modules as well