Issue: SPR-13393
(cherry picked from commit 302a0692)

Issue: SPR-13393

Issue: SPR-13563

Issue: SPR-13554

Issue: SPR-13542

Issue: SPR-13540

This commit migrates all remaining tests from JUnit 3 to JUnit 4, with
the exception of Spring's legacy JUnit 3.8 based testing framework that
is still in use in the spring-orm module.

Issue: SPR-13514

Issue: SPR-13509

Issue: SPR-13213

Issue: SPR-13405

Issue: SPR-13413

Issue: SPR-13409

This commit picks up where 3eacb837
(SPR-13345) left off by adding support for transitive implicit aliases
configured via @AliasFor.

Issue: SPR-13405

This commit removes unnecessary not-null checks for annotation
attribute alias names.

Spring Framework 4.2 introduced support for aliases between annotation
attributes that fall into the following two categories.

1) Alias pairs: two attributes in the same annotation that use
   @AliasFor to declare that they are explicit aliases for each other.
2) Meta-annotation attribute overrides: an attribute in one annotation
   uses @AliasFor to declare that it is an explicit override of an
   attribute in a meta-annotation.

However, the existing functionality fails to support the case where two
attributes in the same annotation both use @AliasFor to declare that
they are both explicit overrides of the same attribute in the same
meta-annotation. In such scenarios, one would intuitively assume that
two such attributes would be treated as "implicit" aliases for each
other, analogous to the existing support for explicit alias pairs.
Furthermore, an annotation may potentially declare multiple aliases
that are effectively a set of implicit aliases for each other.

This commit introduces support for implicit aliases configured via
@AliasFor through an extensive overhaul of the support for alias
lookups, validation, etc. Specifically, this commit includes the
following.

- Introduced isAnnotationMetaPresent() in AnnotationUtils.

- Introduced private AliasDescriptor class in AnnotationUtils in order
  to encapsulate the parsing, validation, and comparison of both
  explicit and implicit aliases configured via @AliasFor.

- Switched from single values for alias names to lists of alias names.

- Renamed getAliasedAttributeName() to getAliasedAttributeNames() in
  AnnotationUtils.

- Converted alias map to contain lists of aliases in AnnotationUtils.

- Refactored the following to support multiple implicit aliases:
  getRequiredAttributeWithAlias() in AnnotationAttributes,
  AbstractAliasAwareAnnotationAttributeExtractor,
  MapAnnotationAttributeExtractor, MergedAnnotationAttributesProcessor
  in AnnotatedElementUtils, and postProcessAnnotationAttributes() in
  AnnotationUtils.

- Introduced numerous tests for implicit alias support, including
  AbstractAliasAwareAnnotationAttributeExtractorTestCase,
  DefaultAnnotationAttributeExtractorTests, and
  MapAnnotationAttributeExtractorTests.

- Updated Javadoc in @AliasFor regarding implicit aliases and in
  AnnotationUtils regarding "meta-present".

Issue: SPR-13345

http://forge.ow2.org/tracker/?func=detail&aid=317578&group_id=23&atid=100023

Mark log4j support classes as deprecated in favor of Apache Log4j 2 (following Apache's EOL declaration for log4j 1.x)

Issue: SPR-13400

Issue: SPR-13394

Additionally, as an optimization, we skip the re-registration step for existing aliases now.

Issue: SPR-13390

This reverts commit d5944c4e.

SocketUtils is used to find available ports on localhost; however,
prior to this commit, SocketUtils incorrectly reported a port as
available on localhost if another process was already bound to
localhost on the given port but not to other network interfaces. In
other words, SocketUtils determined that a given port was available for
some interface though not necessarily for the loopback interface.

This commit addresses this issue by refactoring SocketUtils so that it
tests the loopback interface to ensure that the port is actually
available for localhost.

Issue: SPR-13321

Issue: SPR-13312