This closes #5129.

This closes #5157.

This closes #5153.

This closes #8213.

This closes #5099.

This closes #5127.

Previously, the ResultPartitionWriter implemented the EventListener interface
and was used for event registration, although event publishing was already
handled via the TaskEventDispatcher. Now, we use the TaskEventDispatcher for
both, event registration and publishing.

It also adds the TaskEventDispatcher to the Environment information for a task
to be able to work with it (only IterationHeadTask so far).

This closes #4761.

This closes #5147.

This closes #5146.

This closes #5115.

This closes #5064.

This closes #5152.

This closes #5052.

[FLINK-8174] Mesos RM unable to accept offers for unreserved resources
- added test `OfferTest`

[FLINK-8174] Mesos RM unable to accept offers for unreserved resources
- fix `LaunchCoordinatorTest`

[FLINK-8174] Mesos RM unable to accept offers for unreserved resources
- improved javadocs

[FLINK-8174] Mesos RM unable to accept offers for unreserved resources
- rename `print` to `toString`
- precalculate offer resource values
- extend TestLogger

This closes #5114.

This closes #5118.

The TaskManagerServicesTest was extremely slow because it uses the PowerMockRunner
for a single test case. Additionally some other tests test different settings in
a loop which was quite slow because the PowerMockRunner instrumented all method calls.
Moving the test which required the PowerMockRunner into a separate test class sped up
things by a factor of 50.

Before, AvroUtils were loaded when the class was loaded which didn't
take into account the user-code ClassLoader. Now, we try loading avro
utils with the Thread context ClassLoader.

Replace wait on lock with OneShotLatch to resolve race condition between task
start up and unblocking of invokable.

This closes #5117.

This closes #4504.

The Container Interface was extended in Hadoop 2.9, meaning that the
test would not run when compiling with Hadoop 2.9. Using a mock fixes
this problem.

The WikipediaEditsSourceTest unnecessarily implements an integration
test that starts a FlinkMiniCluster and executes a small Flink program.

This simply creates a source and executes run in a separate thread until
a single WikipediaEditEvent is received.

This closes #5102.

- Minor eager sanity checks
- Use UUID suffix for nickname. As reported in FLINK-8167, the current
  nickname suffix can result in nickname clashes which lead to test
  failures.