DATAGRAPH-483 /  DATAGRAPH-253 REST Transaction support

* Better abstraction layer for interfacing with Neo4j that yields equal performance in embedded and remote mode
* documentation update
* CypherTransaction for transactionally execution remote Cypher
* RestCypherTransactionManager/RemoteCypherTransaction to integrate with JTA / JtaTransactionManager
* SpringCypherRestGraphDatabase / RestAPICypherImpl encapsulating remote communication
* Test update to the cypher implementation / fixes
* Moving RestAPI from java-rest-binding into SDN, removing that dependency