OGM-454 Moving generator types back to "impl", changing implementation of Neo4jSequenceGenerator to work with SPI only
OGM-454 Renaming DocumentStore{Entity|Property|Global}ContextImpl -> BaseDocumentStore{Entity|Property|Global}Context
OGM-454 Moving OgmEntityPersister to "impl"
OGM-454 Removing Instantiator contract from configuration reader SPI; Renaming ClassPropertyReaderContextImpl into DefaultClassPropertyReaderContext
OGM-454 Moving key and meta-data types to "key.spi"
OGM-454 Moving grid dialect operation context types to "dialect.spi"
OGM-454 Moving SchemaDefiner contract to "datastore.spi"
OGM-454 Creating "data.spi" and "data.key.spi" packages for Tuple, Association etc.and key objects