Closes gh-5511

Closes gh-5443

* gh-5546:
  Polish contribution
  Deprecate Undertow container's constructors that have a port parameter

Closes gh-5546

* gh-5575:
  Remove unused unsatisfiedDependency.getInjectionPoint() call

Closes gh-5575

* gh-5572:
  Polish contribution
  Allow Tomcat's minimum threads to be configured via the environment

Closes gh-5572

The changes made in a6c1668b mean that the web starter no longer
depends on spring-boot-starter-validation. Instead, it depends
directly on hibernate-validator. This means that the exclusion of the
validation starter in the TomEE deployment test app no longer matches
anything and hibernate-validator is packaged in the war. This breaks
the application as TomEE ships with Bean Validation 2.0 and the
version of Hibernate Validator being used requires 2.1.

This commit updates the exclusions in the TomEE deployment app so that
hibernate-validator is excluded once again. This allows the app to
use TomEE's bundled Bean Validation implementation.

The stale spring-boot-starter-validation exclusion has been removed
from the Wildfly deployment test app. It is redundant as Wildfly ships
with Bean Validation 2.1. This brings this test app into line with
the Glassfish test app.

Closes gh-5454

* pr/5570:
  Manage jackson-module-jaxb-annotations dependency

Closes gh-5570

* patch-3:
  Remove System.out.println()

Rename @SpringApplicationTest to SpringBootTest and
@SpringApplicationContextLoader to @SpringBootContextLoader.

Fixes gh-5562

Remove the @SpringApplicationConfiguration annotation since it offers
little value over @SpringApplicationTest.

See gh-5562

Refactor internal tests to no longer use @SpringApplicationConfiguration

See gh-5562

This change was missed as part of the work done in 19d8c5e6.

See gh-5306
Closes gh-5543

This commit introduces a new annotation, @AutoConfigureRestDocs,
which can be used to enable auto-configuration of Spring REST Docs.
The auto-configuration removes the need to use Spring REST Docs' JUnit
rule and will automatically configure MockMvc. Combined with the new
auto-configuration for MockMvc it allows a test class to be free of
boilerplate configuration:

@RunWith(SpringRunner.class)
@WebMvcTest
@AutoConfigureRestDocs(outputDir = "target/generated-snippets",
        uriScheme = "https", uriHost = "api.example.com",
        uriPort = 443)
public class ExampleDocumentationTests {

    @Autowired
    private MockMvc mvc;

    @Test
    public void documentIndex() {
        // …
    }

}

For more advanced customization a RestDocsMockMvcConfigurationCustomizer
bean can be used.

If a RestDocumentationResultHandler is found in the context, it will
be passed to the ConfigurableMockMvcBuilder's alwaysDo method as part
of its customization.

Closes gh-5563

Closes gh-5556

In particular it now accepts a list of maps containing
"authority" keys (which is what you get from a standard JSON
decoding of a Spring Security Authentication).

Fixes gh-5482

In the web starter we shouldn't depend explicitly on any EL
implementation, otherwise when people build wars and deploy
them in containers that have their own EL there is a conflict.
We can still depend on hibernate-validator to support
JSR-303 in web apps because the EL implementation comes with
the container.

Fixes gh-5454

* pr/5557:
  Update README.adoc

Closes gh-5557

Add a @SpyBean annotation that can be used to create spies.

Fixes gh-5538

* pr/5553:
  Polish

Closes gh-5553

* gh-5406:
  Upgrade to Lombok 1.16.8

Closes gh-5406

* version-upgrades:
  Upgrade to Logback 1.1.6

Closes gh-5410

Closes gh-5408