Closes gh-8272

See gh-8248

Closes gh-8259

Instead of validating the signature against all the public keys,
we can validate it only against the public key with the kid that
matches the one in the token header.

Closes gh-8126

* pr/8230:
  Polish contribution
  Provide a starter for reactive Spring Data MongoDB

Closes gh-8230

Add autoconfiguration to bootstrap MongoDB Reactive Streams driver
components, reactive Spring Data MongoDB and reactive repositories. Add
bean dependency processor for flapdoodle so embedded MongoDB instances
are configured before bootstraping the reactive MongoDB client.

Add Spring Data MongoDB Reactive starter with blocking and non-blocking
dependencies. MongoDB requires a separate driver that is used in the
`ReactiveMongoTemplate` while `MappingMongoConverter` (shared amongst
blocking/reactive Template API) requires the blocking driver to resolve
DBRefs.

See gh-8230

Closes gh-8247

Closes gh-7666

393cfe50 expanded the scope of spring.profiles.include so that it
could be used in any property source, and not just in a configuration
file. However, it did so in such a way that it would only take effect
when used outside of a configuration file if spring.profiles.active
was also set.

This commit updates ConfigFileApplicationListener so that included
profiles are activated when spring.profiles.active has not be set.

Closes gh-8244

* pr/8215:
  Allow property expansion for *.yaml

Closes gh-8215

This commit improves `SimpleRabbitListenerContainerFactoryConfigurer` to
use a custom `MessageConverter`. If such a bean is present, it is used
for the default factory that is auto-configured.

Closes gh-8194

In Gradle 3.3, when an API that will be removed in 4.0 is called, a
deprecation warning is output as part of the build. Users have noticed
his warning and, quite reasonably, complained about it. Unfortunately,
avoiding the warning requires the use of an API that was introduced in
Gradle 3.x which we can't use directly as we want to remain compatible
with Gradle 2.x.

This commit introduces the use of reflection to call
ProjectDependency.getTargetConfiguration() via reflection when it's
available (Gradle 3) and ProjectDependency.getProjectConfiguration()
when it's not (Gradle 2).

Closes gh-8154

Closes gh-8146

Closes gh-8197

The changes made in 919d0c61 meant that the value of
spring.profiles.active or spring.profiles.include was only processed
when a single property source, the property source for the config file
being read, was available. This meant that any placeholders in those
values would only be resolved against properties in the configuration
file rather than against the entire environment.

This commit updates the binding process so that placeholder resolution
is not performed during binding against a single configuration file.
Once binding has completed, the bounds values are post-processed to
resolve and placeholders that they may contain.

The two-step process described above is used in preference to binding
against the whole environment. This avoids a problem with profiles
that are active or included by property sources in the environment
being processed repeatedly.

Closes gh-8234