This commit picks up where SPR-11483 left off, with the goal of
eliminating all unnecessary inspection of core JDK annotations in
Spring's annotation search algorithms in AnnotatedElementUtils and
AnnotationMetadataReadingVisitor.

Issue: SPR-12989

 - Methods which search for a specific annotation now properly ensure
   that the sought annotation was actually found.

 - Both the "get" and the "find" search algorithms no longer needlessly
   traverse meta-annotation hierarchies twice.

 - Both the "get" and the "find" search algorithms now properly
   increment the metaDepth when recursively searching within the
   meta-annotation hierarchy.

 - Redesigned getMetaAnnotationTypes() so that it doesn't needlessly
   search irrelevant annotations.

 - Documented and tested hasMetaAnnotationTypes().

 - Documented isAnnotated().

Issue: SPR-11514

This commit documents the status quo for the getMetaAnnotationTypes()
method in AnnotatedElementUtils and adds appropriate regression tests to
AnnotatedElementUtilsTests.

In addition, this commit also introduces a SimpleAnnotationProcessor
base class in AnnotatedElementUtils.

Issue: SPR-11514

Issue: SPR-12738

This commit introduces support for finding annotations on abstract,
bridge, and interface methods in AnnotatedElementUtils.

 - Introduced dedicated findAnnotationAttributes() methods in
   AnnotatedElementUtils that provide first-class support for
   processing methods, class hierarchies, interfaces, bridge methods,
   etc.

 - Introduced find/get search algorithm dichotomy in
   AnnotatedElementUtils which is visible in the public API as well as
   in the internal implementation. This was necessary in order to
   maintain backwards compatibility with the existing API (even though
   it was undocumented).

 - Reverted all recent changes made to the "get semantics" search
   algorithm in AnnotatedElementUtils in order to ensure backwards
   compatibility, and reverted recent changes to
   JtaTransactionAnnotationParser and SpringTransactionAnnotationParser
   accordingly.

 - Documented internal AnnotatedElementUtils.Processor<T> interface.

 - Enabled failing tests and introduced
   findAnnotationAttributesFromBridgeMethod() test in
   AnnotatedElementUtilsTests.

 - Refactored ApplicationListenerMethodAdapter.getCondition() and
   enabled failing test in TransactionalEventListenerTests.

 - AnnotationUtils.isInterfaceWithAnnotatedMethods() is now package
   private.

Issue: SPR-12738, SPR-11514, SPR-11598

This commit introduces support in AnnotatedElementUtils for finding
annotations declared on interfaces at the type level.

NB: this commit does not include support for finding annotations
declared on interface methods.

In order to maintain backward compatibility with @Transactional
annotation attribute processing, a new getAnnotationAttributes() method
has been added to AnnotatedElementUtils that provides a flag to control
whether interfaces should be searched.
SpringTransactionAnnotationParser and JtaTransactionAnnotationParser
have been updated accordingly to ensure that interfaces are not
unintentionally searched in the @Transactional resolution process.

This commit also introduces additional tests and updates TODOs for
SPR-12738.

Issue: SPR-12944, SPR-12738

Prior to this commit, the search algorithm used by the
findAnnotation(Method, Class) method in AnnotationUtils only found
direct annotations or direct meta-annotations (i.e., one level of
meta-annotations).

This commit reworks the search algorithm so that it supports arbitrary
levels of meta-annotations on methods. To make this possible, a new
findAnnotation(AnnotatedElement, Class) method has been introduced in
AnnotationUtils.

This fix also allows for the @Ignore'd tests in
TransactionalEventListenerTests to be re-enabled.

Issue: SPR-12941

- Now correctly using @test(expected=...) where appropriate.

- Renamed DefaultConversionTests to DefaultConversionServiceTests.

- Moved all tests related to DefaultConversionService from
  GenericConversionServiceTests to DefaultConversionServiceTests.

- No longer printing to System.out.

- Removed all duplicate instantiation of conversion services.

- Now using Java 8 streams to simplify implementations of custom test
  converters. Also using streams in tests where appropriate.

Issue: SPR-12846

Issue: SPR-12147

Issue: SPR-12549

Issue: SPR-12785

Prior to this commit, the implementation of equals() in EncodedResource
was based solely on the resource and encoding. Thus, if a Charset were
specified instead of an encoding, invocations of equals() would not
work as expected.

This commit addresses this issue by including the charset in the
implementation of equals() and introducing corresponding tests in a new
EncodedResourceTests class. Furthermore, this commit makes
EncodedResource immutable and updates all Javadoc to reflect support
for the encoding and charset properties.

Issue: SPR-12767

Issue: SPR-12766

This commit ensures Resources have consistent, non-empty, meaningful
implementations for getDescription(), thus ensuring that calls to
toString() (e.g., in log statements) no longer return an empty String.

This commit also polishes the Javadoc for various Resource
implementations.

Add StreamConverter to provide full support for converting
java.util.stream.Stream instances to and from collections or arrays.

Also attempt to convert the element type if necessary.

StreamConverter is registered by default in the DefaultConversionService
as long as Java8 is available.

Issue: SPR-12175

Issue: SPR-12701

Previously, the `@order` annotation was managed in an inconsistent way
when placed at the implementation level. For simple beans, it was
discovered properly but wasn't for beans requiring a proxy.

OrderComparator.SourceProvider now explicitly allows to return several
order sources; the default implementation returns not only the factory
method (if  any) but also the target class if it happens to be different
from the class of the bean.

Issue: SPR-12636

This commit introduces test methods in CollectionFactoryTests that
demonstrate how the APIs for createCollection() and createMap() are not
type-safe, specifically regarding the use of generics, raw types, and
casting.

SPR-12483 introduced automatic type conversion support for EnumSet and
EnumMap. However, the corresponding changes in CollectionFactory
contradict the existing contract for the "create approximate" methods
by creating a copy of the supplied set or map, thereby potentially
including elements in the returned collection when the returned
collection should in fact be empty.

This commit addresses this issue by ensuring that the collections
returned by createApproximateCollection() and createApproximateMap()
are always empty.

Furthermore, this commit improves the Javadoc throughout the
CollectionFactory class.

Issue: SPR-12533

This commit introduces test methods in CollectionFactoryTests that
demonstrate how the APIs for createApproximateCollection() and
createApproximateMap() are not type-safe, specifically regarding the use
of generics, raw types, and casting.

This commit improves error handling in CollectionFactory by asserting
preconditions.

In addition, this commit introduces ConnectionFactoryTests.

Issue: SPR-12483

Issue: SPR-12473
(cherry picked from commit 5ac86803)

MutablePropertySources uses an internal CopyOnWriteArrayList for defensiveness against concurrent modifications

Issue: SPR-12428

Prior to this commit, JOptCommandLinePropertySource prevented the
possibility of non-String option arguments. This effectively prevents
the use of JOpt's #ofType support (which allows specifying custom
argument types).

Now, non-String arguments are detected and converted to strings as
necessary. JOpt's #ofType now works as expected. A test has been added
to cover this case.

AnnotationUtils favors local composed annotations over interface annotations and consistently logs introspection failures via lazily initialized logger

Issue: SPR-12355
Issue: SPR-12325
Issue: SPR-12329