Split the Gradle invocation in the jenkins.sh script into two commands so
we can fail fast for validation checks such as compile errors and checkstyle
errors.

Reviewers: Manikumar Reddy <manikumar.reddy@gmail.com>, Ismael Juma <ismael@juma.me.uk>

findBugs is abandoned, it doesn't work with Java 9 and the Gradle plugin will be deprecated in
Gradle 5.0: https://github.com/gradle/gradle/pull/6664

spotBugs is actively maintained and it supports Java 8, 9 and 10. Java 11 is not supported yet,
but it's likely to happen soon.

Also fixed a file leak in Connect identified by spotbugs.

Manually tested spotBugsMain, jarAll and importing kafka in IntelliJ and running
a build in the IDE.

Author: Ismael Juma <ismael@juma.me.uk>

Reviewers: Colin Patrick McCabe <colin@cmccabe.xyz>, Dong Lin <lindong28@gmail.com>

Closes #5625 from ijuma/kafka-5887-spotbugs

This ensures that the whole test suite is executed even
if there are failures. It currently stops at a module
boundary if there are any failures. There is a discussion
to change the gradle default to stop after the first test failure:

https://github.com/gradle/gradle/issues/6513

`--continue` is recommended for CI in that discussion.

Author: Ismael Juma <ismael@juma.me.uk>

Reviewers: Dong Lin <lindong28@gmail.com>

Closes #5599 from ijuma/jenkins-script-continue

Reviewers: Ewen Cheslack-Postava <ewen@confluent.io>

Author: Ewen Cheslack-Postava <me@ewencp.org>

Reviewers: Ismael Juma <ismael@juma.me.uk>

Closes #3186 from ewencp/kafka-4459-rat-jenkins

Author: Colin P. Mccabe <cmccabe@confluent.io>

Reviewers: Ismael Juma <ismael@juma.me.uk>

Closes #2842 from cmccabe/findbugs-xml

Author: Colin P. Mccabe <cmccabe@confluent.io>

Reviewers: Ismael Juma <ismael@juma.me.uk>

Closes #2805 from cmccabe/KAFKA-5013

This uses JUnit Categories to identify integration tests. Adds 2 new build targets:
`integrationTest` and `unitTest`.

Author: Damian Guy <damian.guy@gmail.com>

Reviewers: Eno Thereska <eno@confluent.io>, Ewen Cheslack-Postava <ewen@confluent.io>, Ismael Juma <ismael@juma.me.uk>

Closes #2695 from dguy/junit-categories

* Add quotes to `$` in shell scripts
This is necessary for correct processing of quotes in the
user command.

* Minor improvements to AclCommand messages

* Use a principal with a space in `SslEndToEndAuthorizationTest`
This passed without any other changes, but good avoid regressions.

* Clean-up `TestSslUtils`:
Remove unused methods, fix unnecessary verbosity and don't set security.protocol (it should be done at a higher-level).

Author: Ismael Juma <ismael@juma.me.uk>

Reviewers: Grant Henke <granthenke@gmail.com>, Jun Rao <junrao@gmail.com

Closes #818 from ijuma/kafka-3152-kafka-acl-space-in-principal

KAFKA-1081 Clean up shell scripts. Removed re-run of failed command. Use exec instead of subprocess execution.

Misc. minor house-keeping fixes: add reasonable GC settings, fix up README, fix up example configs, fix the logging for tools, use a log directory for logs instead of the root directory.

KAFKA-141 Check and make sure that the files that have been donated have been updated to reflect the new ASF copyright;patched by nehanarkhede; reviewd by jjkoshy

git-svn-id: https://svn.apache.org/repos/asf/incubator/kafka/trunk@1180185 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/incubator/kafka/trunk@1180117 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/incubator/kafka/trunk@1180110 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/incubator/kafka/trunk@1178659 13f79535-47bb-0310-9956-ffa450edef68