Closes gh-5532

Closes gh-5309

* pr/5488:
  Upgrade Spring AMQP to 1.6.0.M2

Closes gh-5488

* pr/5521:
  Polish contribution
  Add `defaultValue` property in springProperty tag

Closes gh-5521

This commit adds a `defaultValue` attribute to the `springProperty` tag
of Logback. That attribute can be used to specify a default value.

Closes gh-5447

This commit adds a `spring.jersey.filter.load-on-startup` property used to
customize the startup priority of the Jersey servlet.

Closes gh-5100

This commit updates `Sanitizer` to sanitize by default a key containing
`token`.

Closes gh-5462

* pr/5512:
  Polish contribution
  Add check for non empty list of factories

Closes gh-5512

It was seeen that if a different plugin was used to package Spring Boot
that the project would load but no autoconfiguration actually took
place and many features were mysteriously not working.  Adding a check
to ensure that some factories are always loaded as this is expected.

Closes gh-5465

* pr/5498:
  Polish contribution
  Add useAlwaysMessageFormat configuration key

Closes gh-5498

Allow to configure the `useAlwaysMessageFormat` attribute of
`MessageSource` via configuration.

Closes gh-5483

Previously, the default BuildInfo task created by the DSL was called
buildInfo. Due to Gradle's lack of namespacing for tasks, this meant
there was a slight risk that it could clash with another task. It
also didn't following the naming used by Boot's run task which is
named bootRun.

This commit renames the default BuildInfo task to bootBuildInfo to
match bootRun and to hopefully avoid clashes with tasks from other
plugins.

Closes gh-5518

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

Closes gh-5504

* pr/5514:
  Add graphql-spring-boot-starter reference

Closes gh-5514

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/5508:
  Polish

Closes gh-5508

* pr/5500:
  Fix MockDefinition.toString()

Closes gh-5500

Rename the internal versions of OutputCapture to prevent accidental
import.

See gh-5492