Closes gh-8431

* pr/8143:
  Fix indentation
  Clarify usage of @ImportResource in doc

Closes gh-8143

See gh-8143

* pr/8460:
  Upgrade to Spring Integration 4.3.8.RELEASE

Closes gh-8460

Closes gh-8461

* pr/8227:
  Refine engine counter logic
  Polish web containers stop contribution
  Ensure web containers are stopped after close

Update counter logic to prevent negative values. Since the stop method
can now be called more than once, it was possible for the counter to
move into negative values.

See gh-8227

See gh-8227

Update `EmbeddedServletContainer` implementations to ensure that stop
can be called even if start has not. This allows servers that are
partially started during `initialize()` to still be shut down.

This commit fixes a regression caused by commit 0af53b36.

See gh-8036
Fixes gh-8224
Closes gh-8227

Update `HealthMvcEndpoint` to respect `ManagementServerProperties`
roles. Prior to this commit the `HealthMvcEndpoint` directly loaded
roles rather than using bound properties. This meant that list values
from yaml were not respected.

Fixes gh-8314

Update DataSourceInitializedPublisher to always attempt to obtain the
published DataSource directly from the EntityManager. In the case where
the EntityManager doesn't provide a DataSource, the previous logic is
used.

Fixes gh-8296

If Spring Security is on the classpath and `isUserInRole` returns false,
check if user has the authority to access the actuator endpoints.

Fixes gh-8255

Instead of entirely skipping the interceptor, we will be additionally
checking for authorities.

If Spring Security is on the classpath, the role check can be done
as part of the ManagementWebSecurityConfigurerAdapter.

Fixes gh-8255

* gh-8458:
  Upgrade to Spring AMQP 1.6.8.RELEASE

Closes gh-8458

See gh-8444

Closes gh-8354

Closes gh-8455

Closes gh-8454

Closes gh-8453

Closes gh-8452

Closes gh-8451

Closes gh-8450

Closes gh-8449

Closes gh-8448

Closes gh-8447

Closes gh-8446

Closes gh-8269