See gh-5287

Ensure any ChildManagementContext created to start a management server
on a different port uses the same EmbeddedServletContainerFactory type.

Fixes gh-5474

Update ServerProperties so that `null` values are not applied when
customizing the EmbeddedServletContainerFactory. Primarily changed to
stop `server.undertow.accesslog.enabled` from being blindly applied.

Fixes gh-5515

Update the auto-configured MessageChannelMetricWriter with
@ExportMetricWriter so that metrics are actually exported.

Fixes gh-5517

Update JettyEmbeddedServletContainerFactory so that requests other than
just GET, POST and HEAD are handled by the ErrorHandler.

Fixes gh-5367

To overcome command length limits on Windows, IntelliJ IDEA may launch
an application with a single jar on the classpath that contains that
application's actual classpath in the Class-Path attribute of its
manifest. This would prevent DevTools restarts from working as it
only considered the single jar's URL when identifying changeable URLs
and ignored the URLs added to the classpath via the jar's manifest.

This commit updates ChangeableUrls when it is created from a
URLClassLoader to consider the Class-Path manifest attribute of any
jars in the class loader's URLs. This allows the full classpath to
be considered when identifying URLs that are changeable and that
need to be monitored for restart triggering.

Closes gh-5127

* gh-5289:
  Polish contribution
  Update JarURLConnection to support jar:file://… URLs

Previously, JarURLConnection would fail when created with a URL that
began with jar:file:// as the double-slash is not included in jarFile.getUrl().getFile().

This commit updates JarURLConnection to normalise the value return from
url.getFile() to remove a double-slash when present.

Fixes gh-5287
Closes gh-5289

* gh-5397:
  Improve repeatability of launch script tests

Previously, tags were used for CentOS and Ubuntu images that may
change over time. This commit updates the Dockerfiles to use fixed
base images. For Ubuntu, a fixed tag is available. For CentOS we
have to resort to using the digest.

Closes gh-5397

* gh-5394:
  Update launch.script so popd does not print directory name to stdout

Closes gh-5394

* gh-5615:
  Remove a duplicate test

Closes gh-5615

Closes gh-5588

Closes gh-5587

Closes gh-5586

Closes gh-5585

Closes gh-5584

Closes gh-5583

Closes gh-5582

Closes gh-5581

Closes gh-5580

Closes gh-5579

Closes gh-5578

Closes gh-5577

Closes gh-5568

* version-upgrades:
  Upgrade to Logback 1.1.6

Closes gh-5410

Closes gh-5408

Previously, FindMainClassTask would look for a property named main
on any class named run. This was based on the assumption that the
run task would be a JavaExec task (typically provided by the
application plugin). If the run task was not a JavaExec task (more
accurately, if it did not have a main property) this would result in
a build failure due to trying to read a non-existent property.

This commit updates FindMainClassTask to only use the main property
of the run task if the task is a JavaExec task. This guarantees that
the property will exist on the task, and unlike using any property
named main on a task named run, also guarantee that its value will
refer to a Java class with a main method.

Closes gh-5501

This commit fixes `IntegrationAutoConfiguration` to actually rely on the
auto-configured `MBeanServer` rather than attempting to create it again.

If JMX support is disabled, no attempt to register integration-related
MBeans is made.

Closes gh-5309

Add a reference ot underscore notation

Closes gh-5268

Restore Spring Boot 1.3.2 behavior of re-applying system properties
when SLF4J based loggers are re-initialized. Reapplying system
properties is required when using the Spring Cloud config server since
PropertySourceBootstrapConfiguration directly calls the system
initialize method.

Fixes gh-5491

* pr/5489:
  Upgrade Spring AMQP to 1.5.5.RELEASE

Closes gh-5489

Closes gh-5264