Some noise reduction.

This allows us to specify multiple executions that copy different file sets without having to worry what side-effects it may have.

We build a separate jar for BashJavaUtils with bundled log4j classes and
a configuration that logs to the stdout. Using this jar we run the
utility to capture the output. Out of the last line we extract jvm
parameters. The rest we pass as an environment variable (INHERITED_LOGS)
to the TaskManager process.

As part of the EnvironmentInformation printing we log whatever was
passed through the INHERITED_LOGS in the TM/JM process.

This closes #10850

FLINK-14905 introduced a multi-release approach to bundle libraries
for different JDK versions. However, the multi-release flag was not
correctly set, which effectively disabled the mechanism and lead to
incomplete dependencies on Java 11. This commit fixes the setup, such
that the Java 11 libraries are correctly loaded.

This closes #9957 .

* Add new Docker Playgrounds section to Getting Started documenation section
* Add new count click events example jobs

This closes #9192.

This closes #9133.

Remove the legacy flink-libraries/flink-ml and flink-libraries/flink-ml-uber

This closes #8526

Please note that there is also a static version of netty-tcnative but we
currently do not distribute it due to licensing issues. Once openSSL completes
its switch to Apache License v2, we can provide this as well and maybe even
make that one default (by putting it into lib/). Since there are to many things
which may go wrong with the dynamically-linked library (based on the system you
run on), we provide this only in opt/.

This closes #8590.

Note: Currently only flink planner is supported. The blink planner will be supported after the planner discovery is supported which is part of the work of FLIP32.

This closes #8474

This closes #8472

[FLINK-12311][python] Add base python framework and Add Scan, Projection, and Filter operator support

This closes #8267

make travis tests green

fix documents, refine shell file name and optimize program logic.

Adjust the code examples in python documents to be consistent with scala documents.

Refactor flink-python project structure, remove java file from flink-python package.

delete unnecessary dependency and plugins.

This also adadpts update_branch_version.sh to correctly update versions
that have a prefix.

This commit splits the flink-table module into multiple submodules in
accordance with FLIP-32 (step 1).

The new module structure looks as follows:

flink-table-common
       ^
       |
flink-table-api-java <------- flink-table-api-scala
       ^                                 ^
       |                                 |
flink-table-api-java-bridge    flink-table-api-scala-bridge
       ^
       |
flink-table-planner

The module structure assumes that the type system has been reworked such
that only one table environment exists for both Java and Scala users.

The module `flink-table-planner` contains the content of the old
`flink-table` module. From there we can distribute ported classes to
their final module without breaking backwards compatibility or
force users to update their dependencies again.

For example, if a user wants to implement a pure table program in Scala,
`flink-table-api-scala` and `flink-table-planner` need to be
added to the project.

Until we support pure table programs, `flink-table-api-scala/java-bridge`
and `flink-table-planner` need to be added to the project.

This closes #7587.