Maintain a deterministic port ordering, so we can have expectations on which endpoint is behind which port index.

This closes #6288.

Use the Jepsen framework (https://github.com/jepsen-io/jepsen) to implement
tests that verify Flink's HA capabilities under real-world faults, such as
sudden TaskManager/JobManager termination, HDFS NameNode unavailability, network
partitions, etc. The Flink cluster under test is automatically deployed on YARN
(session & job mode) and Mesos.

Provide Dockerfiles for local test development.

This closes #6240.

This closes #6129.

This closes #6305.

The upgraded ciphers are not yet supported on all platforms and JDK versions, making
the getting-started process rough. Instead, we document our recommendation to set these
values in the configuration.

This reverts "[FLINK-9310] [security] Update standard cipher suites for secure mode"

This closes #6102.

This closes #6274.

This closes #6310.

This closes #6304.

This closes #6170.

This adds the Java and Scala API for performing an IntervalJoin.
In jave this will look like:

Example:

```java
keyedStream.intervalJoin(otherKeyedStream)
    .between(Time.milliseconds(-2), Time.milliseconds(2)) // lower and upper bound
    .upperBoundExclusive(true) // optional
    .lowerBoundExclusive(true) // optional
    .process(new IntervalJoinFunction() {...});
```

This closes #5482.

This closes #6313.

This closes #6306.

This closes #6308.

This closes #6298.

If an assertion in the test fails and as a result the cleanup fails, in most
tests the original assertion was swallowed making it hard to debug.

Furthermore, #testConcurrentRecycleAndRelease2() does even not clean up at all
if successful.

This closes #6271

This closes #6291

This feature is currently only exposed on StreamTransformations (internal API) rather
than in the public API, because it is a hidden expert feature.

This closes #6309

In order to avoid race conditions between resource clean up, we now wait for the proper
termination of a previously running JobMaster responsible for the same job (e.g. originating
from a job recovery or a re-submission).

This closes #6279.

This closes #6277.

Before, a window Trigger would not be invoked if the window is empty at
the time of the timer firing. Now the Trigger is always invoked.

As a side effect, this resolves FLINK-9687.

This closes #6286.

This closes #6285.

This closes #6295.

This closes #6164.

This closes #6230.

This closes #6247.

This closes #6184.

This closes #6292.

This closes #6263.

[FLINK-9776] [runtime] Stop sending periodic interrupts once executing thread leaves user function / operator code.

This closes #6275

This closes #6290

- Simplify code and fix various bugs
- Add more tests
- Refactor various names for descriptors and variables
- Make 'from' property mandatory
- Make LiteralValue public API

This closes #6090.

This commit does not include the integration with checkpointing.

This closes #6276.