This commit makes sure that the `skip` command-line property can be used
for all goals of the maven plugin.

A dedicated sample for integration tests has also been added as this
change may confuse users, especially those who wish to skip a certain
goal and not the plugin execution altogether.

Closes gh-7313

See gh-7362

This commit deprecates `server.max-http-post-size` and introduces a
dedicated property for each supported  container. In particular, Undertow
can now define a max size higher than 2GB.

Closes gh-7362

Closes gh-7476

This commit auto-configures `MethodValidationPostProcessor` if necessary
when a JSR-303 validator implementation is detected on the classpath.

Closes gh-6228

* pr/7462:
  Polish contribution
  Fix undertow session persistence with spring-boot-devtools

Closes gh-7462

Fixes gh-7460

If `OnBeanCondition` is used with a `String` literal representing the
fully qualified name of a bean and such type does not exist, it
gracefully manages it as if it was not found. Prior to this commit, an
exception would be thrown if any related class such as the parent
class does not exist.

This commit handles this additional case, catching `NoClassDefFoundError`
the same way it did handle `ClassNotFoundException`. That way, a
missing type will now be considered as absent if it's not on the
classpath.

Closes gh-7459

Previously, two or more `@DataJpaTest` tests in the same test suite were
sharing the same in-memory database instance. This commit makes sure
that `TestDatabaseAutoConfiguration` creates a unique embedded database
for each test it operates on.

Closes gh-7473

Closes gh-7463

This commit reverts 7e2d0fd1 so that the Couchbase auto-configuration can
work without Spring Data again. It also removes the `Class` reference to
a Spring Data class to a `String` reference to make sure the condition
operates properly when said class isn't on the classpath.

Closes gh-7453

Closes gh-7320

This commit allows to configure special customizers to be used by
Cluster.

Closes gh-7312

Consider the following two URLs:

jar:file:/test.jar!/BOOT-INF/classes!/foo.txt
jar:file:/test.jar!/BOOT-INF/classes/foo.txt

They both reference the same foo.txt file in the BOOT-INF/classes
directory of test.jar, however the first URL does so via the
nested BOOT-INF/classes archive. Previously, this difference in the
URLs would lead to PathMatchingResourcePatternResolver returning two
resources for foo.txt when asked to find all resources matching the
pattern classpath*:/**/*.txt.

This commit updates our Handler that is used for jar: URLs to consider
the two URLs above to be equivalent such that url1 is equal to url2
and the two urls will produce the same hash code.

Closes gh-7449

* pr/7457:
  Polish upgrade to Spring Session 1.3.0.RC1
  Upgrade Spring Session to 1.3.0.RC1

Closes gh-7457

See gh-7457