OGM-408 Creating Infinispan descriptor class; Moving Infinispan property constants to InfinispanProperties
OGM-408 Moving Ehcache property constants to new Ehcache descriptor type
OGM-408 Fixing docs
OGM-408 Creating Neo4j descriptor class; Moving Neo4j property constants to Neo4jProperties
OGM-408 Using ConfigurationPropertyReader for retrieving GraphDatabaseServiceFactory
OGM-408 Establishing OgmProperties for properties used by several stores
OGM-408 Making sure all ways of specifying the datastore provider work
OGM-408 Moving MongoDB property constants to OgmProperties and MongoDBProperties
OGM-408 Using common properties for configuring CouchDB
OGM-408 Making CouchDB's association storage option a generic document store option
OGM-408 Using @AssociationStorage option and property from core for MongoDB
OGM-408 Unifying access to association storage configuration property
OGM-408 Moving common configuration constants to OgmProperties
OGM-408 Unifying retrieval of common properties

* Extending ConfigurationPropertyReader to read simple configuration properties
* Establishing DocumentStoreConfiguration to access properties common to MongoDB and CouchDB
OGM-408 Adding PropertyValidator SPI to ConfigurationPropertyReader
OGM-408 Exposing properties configured as implementation type via property()

* Making inner types from ConfigurationPropertyReaders top-level types
* Establishing configuration reader package