This commit partially reverts the changes made in ec470fbe. While
the started message continues to be logged before any application and
command line runners are called, the publishing of
ApplicationReadyEvent now happens after the runners have been called.
Additionally, a new event, named ApplicationStartedEvent, has been
introduced. This new event is published after the context has been
refreshed but before any application and command line runners are
called.

Closes gh-11484

The reworking of the events described above also means that either
an ApplicationReadyEvent or an ApplicationFailedEvent will be
published and the latter should never be published once the former
has been published.

Closes gh-11485

This commits improves the cache auto-configuration for Redis by looking
up a custom "RedisCacheConfiguration" bean that allows to take full
control over the `RedisCacheManager`.

Closes gh-11599

See gh-11428

Closes gh-11428

This commit adds SSL client Authentication support
to Reactor Netty and adds the relevant tests to
`AbstractReactiveWebServerFactoryTests` for all servers.

Fixes gh-11488

This commit applies `server.undertow.*` configuration properties
to Undertow when configured as a reactive web server.

See gh-11500

This commit applies `server.jetty.*` configuration properties
to Jetty when configured as a reactive web server.

It also removes some infrastructure support for Jetty 8, which
is not supported anymore in Spring Boot 2.0 (partial fix for
gh-11504).

See gh-11500

This commit applies most `server.tomcat.*` configuration
properties to Tomcat when set up as a reactive web server.

Some Servlet-specific properties are not applied:

* server.tomcat.additional-tld-skip-patterns
* server.tomcat.redirect-context-root
* server.tomcat.use-relative-redirects

Fixes gh-11334

Closes gh-11331

* pr/11591:
  Polish "Make GsonAutoConfiguration align with JacksonAutoConfiguration"
  Make GsonAutoConfiguration align with JacksonAutoConfiguration

Closes gh-11591

See gh-11591

Backport commit d439b737 to upgrade launch integration tests to
use docker-java 3.0.x.

Closes gh-11203

See gh-11023

Closes gh-11023

* pr/11587:
  Fix imports order for Checkstyle

Closes gh-11587

Closes gh-11022

Fixes gh-11273

Extract properties used by RestDocs to their own class.

See gh-10696

This commit makes sure that properties-based resource bundle location
with a dot is detected. It also harmonizes the description of the
configuration key as our support is not stricly matching the convention.

Closes gh-10092

* gh-10969:
  Polish "Add auto-configuration for using REST Docs with WebTestClient"
  Add auto-configuration for using REST Docs with WebTestClient

Closes gh-10696

See gh-10969

Closes gh-11579

It's a new module in 3.0 and we're using 2.53.x in 1.5.x.

See gh-11528

Closes gh-11578

Closes gh-11576

* pr/11534:
  Use instance equality for Class