- call new start() method of FlinkMiniCluster

This closes #1085.

[hotfix] [gelly] Remove unintended calls to getExecutionEnvironment in VertexCentricIteration and GatherSumApplyIteration

This closes #1031

[FLINK-2448] [tests] Create new Test Environments on every call to getExecutionEnvironment and allow sharing of job execution results

This closes #1067

This prevents possible null pointers when the JVM shuts down before the I/O manager was fully started.

* modified algorithm as explained in the issue
* updated method documentation

[FLINK-2590] reducing required bit shift size

* maximum bit size is changed to getNumberOfParallelSubTasks() - 1

This closes #1075.

This closes #1076

This closes #1080

- move createCopySerializable to core's CommonTestUtils
- rename CommonTestUtils createCopy to createCopyWritable
- adapt the tests to use core's CommonTestUtils where applicable

This closes #1081.

- fixed warning by adding a catch all case
- corrected indention of code block

hint: use -w to ignore the whitespace in the diff,
      e.g. git log -u -w

[FLINK-2291] [runtime] Add ZooKeeper support to elect a leader from a set of JobManager. The leader will then be retrieved from ZooKeeper by the TaskManagers.

Refactors FlinkMiniCluster to support multiple JobManager

Adds proper remote address resolution for actors

Clean up of LeaderElection and LeaderRetrievalService. Removes synchronization to avoid deadlock.

Adds ZooKeeper start option to TestBaseUtils.startCluster

Removes registration session IDs, using the leader session IDs instead. Sets the leader session ID
 directly in the grantLeadership method. Let the LeaderElectionService select the leader session I
D. Return leader session ID to LeaderRetrievalListeners.

Removes direct ActorRef interaction

Introduces LeaderRetrievalService for the Client and the CliFrontend.

Make ApplicationClient to use the LeaderRetrievalService for JobManager resolution

Adds LeaderElection/Retrieval tests

Added test for exception forwarding from the CuratorFramework to a Contender

Adds test job submission with changing leaders

Adds new test cases for job cleanup after leader election change

Adds new LeaderChangeStateCleanup test case

Adds LeaderElectionRetrievalTestingCluster

Introduces ListeningBehaviour for job submissions

Relocation of org.apache.curator in flink-shaded-hadoop jar

Adds Apache ZooKeeper and Apache Curator to LICENSE and NOTICE files

Increases zookeeper connection timeout to 20000 ms for the KafkaITCase to fix failing tests on Travis

Increased timeouts of ZooKeeperLeaderElectionTest for Travis

Makes the WebInfoServer and the WebRuntimeMonitor to use the LeaderRetrievalService to retrieve the current leading JobManager

Adds proper synchronization to ZooKeeperLeaderElectionService. Fixes StateCheckpointedITCase and PartitionedStateCheckpointingITCase

Adds configuration description for new ZooKeeper configuration values

Fixed port selection of JobManager at startup

Improves logging output

Extends masters file to also specify the webui ports

Adds proper network interface resolution by retrieving the current leader address

Makes the ZooKeeperLeaderElectionService write the leader information in ephemeral nodes so that the information is deleted once the leader has terminated. Fixes a bug in the TaskManager due to call by name semantics of scheduler.scheduleOnce.

Adds jobManagerURL to TriggerTaskManagerRegistration message

Enables findConnectingAddress to use the ZooKeeperLeaderRetrievalService. This allows to test the connection to a possibly changing master node.

Changes startup scripts to respect the recovery mode instead of the ZK_QUORUM

Adjust travis log file to only log zookeeper errors

Updates high availability setup guide

Adds TestLogger to leader election tests

This closes #1016.

[tests] Improve and combine iteration tests with aggregators (less static sharing, collect(), parallel execution)

[FLINK-2543] [core] Make exception communication and result/failure notifications consistent with respect to serialization of exceptions

Send exceptions from JM --> JC in serialized form.
Exceptions send from the JobManager to the JobClient were relying on
Akka's JavaSerialization, which does not have access to the user code classloader.

This closes #1048

- move SerializedValue from runtime to core
- unified code to deserialize accumulators

This closes #1072.

Closes #1071

This closes #1043

This closes #1044

This closes #1070

This closes #1062

[FLINK-2587] [streaming] Make sure that close() is not called while checkpoint methods are in progress.

[FLINK-2584] [java api] Downgrade version of javakaffee kryo serializers, for compatibility with kryo 2.4

  - reworked package structure of utils and wordcount.stormoperators package
  - reword class hierarchy of *FileSpout and *InMemorySpout
  - fixed pom.xml to assembly jars correctly
  - simplified example jar file names
  - replace maven-assembly-plugin with maven-shade-plugin (removed assembly.xml file)
  - extended README and documenation to building and using correct jars

Additional minor changes:
 - comment typo in FlinkSubmitter
 - removed version number in hardcoded jar file name

This closes #1037

  - Extend ValueTypeInfo to check whether the type is basic value or not
  - Extend TupleTypeInfo to support Value types
  - Add three unit tests and an integration test
  - Rename CsvReaderWithPOJOITCase to CsvReaderITCase
  - Refactor CsvReaderITCase to use collect method

This closes #1053

This closes #1065

[FLINK-2386] [kafka connector] Move Kafka connector classes to 'org.apache.flink.streaming.connectors.kafka'

[FLINK-2386] [kafka connector] Remove copied Kafka code again. Implemented our own topic metadata retrieval.

This closes #1039