Update `StandardAnnotationMetadata` and `AnnotationMetadataReadingVisitor`
so that `java.lang.annotation` annotations are consistently skipped.

Closes gh-22885

org.junit.Assert.assertThat() is deprecated as of JUnit 4.13.

See gh-22894

Closes gh-22766

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://www.apache.org/licenses/ with 1 occurrences migrated to:
  https://www.apache.org/licenses/ ([https](https://www.apache.org/licenses/) result 200).
* [ ] http://www.apache.org/licenses/LICENSE-2.0 with 6515 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://www.apache.org/licenses/ with 1 occurrences migrated to:
  https://www.apache.org/licenses/ ([https](https://www.apache.org/licenses/) result 200).
* [ ] http://www.apache.org/licenses/LICENSE-2.0 with 6625 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).

Issue: SPR-17347

use assertNull instead of assertEquals(null, value),
declare delta as double value in assertEquals

This commit adds a "spring-context-indexer" module that can be added to
any project in order to generate an index of candidate components defined
in the project.

`CandidateComponentsIndexer` is a standard annotation processor that
looks for source files with target annotations (typically `@Component`)
and references them in a `META-INF/spring.components` generated file.

Each entry in the index is the fully qualified name of a candidate
component and the comma-separated list of stereotypes that apply to that
candidate. A typical example of a stereotype is `@Component`. If a
project has a `com.example.FooService` annotated with `@Component` the
following `META-INF/spring.components` file is generated at compile time:

```
com.example.FooService=org.springframework.stereotype.Component
```

A new `@Indexed` annotation can be added on any annotation to instructs
the scanner to include a source file that contains that annotation. For
instance, `@Component` is meta-annotated with `@Indexed` now and adding
`@Indexed` to more annotation types will transparently improve the index
with additional information. This also works for interaces or parent
classes: adding `@Indexed` on a `Repository` base interface means that
the indexed can be queried for its implementation by using the fully
qualified name of the `Repository` interface.

The indexer also adds any class or interface that has a type-level
annotation from the `javax` package. This includes obviously JPA
(`@Entity` and related) but also CDI (`@Named`, `@ManagedBean`) and
servlet annotations (i.e. `@WebFilter`). These are meant to handle
cases where a component needs to identify candidates and use classpath
scanning currently.

If a `package-info.java` file exists, the package is registered using
a "package-info" stereotype.

Such files can later be reused by the `ApplicationContext` to avoid
using component scan. A global `CandidateComponentsIndex` can be easily
loaded from the current classpath using `CandidateComponentsIndexLoader`.

The core framework uses such infrastructure in two areas: to retrieve
the candidate `@Component`s and to build a default `PersistenceUnitInfo`.
Rather than scanning the classpath and using ASM to identify candidates,
the index is used if present.

As long as the include filters refer to an annotation that is directly
annotated with `@Indexed` or an assignable type that is directly
annotated with `@Indexed`, the index can be used since a dedicated entry
wil be present for that type. If any other unsupported include filter is
specified, we fallback on classpath scanning.

In case the index is incomplete or cannot be used, The
`spring.index.ignore` system property can be set to `true` or,
alternatively, in a "spring.properties" at the root of the classpath.

Issue: SPR-11890

Issue: SPR-14427

Issue: SPR-13188

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

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

ClassMetadata exposes isAnnotation() now, and correctly returns false from hasSuperClass() for interfaces and annotations

Issue: SPR-11711

AnnotationMetadataReadingVisitor passes metaAnnotationMap into getMergedAnnotationAttributes algorithm, for finding out about applicable overrides

Issue: SPR-11649

Prior to this commit, invoking the getMergedAnnotationAttributes()
method in AnnotationReadingVisitorUtils resulted in mutation of the
internal state of the ASM-based annotation metadata supplied to the
method.

This commit fixes this issue by making a copy of the original
AnnotationAttributes for the target annotation before merging attribute
values from the meta-annotation hierarchy.

This commit also introduces a slight performance improvement by
avoiding duplicate processing of the attributes of the target
annotation.

Issue: SPR-11710

Changes introduced in conjunction with issue SPR-11475 altered the
behavior of StandardAnnotationMetadata such that annotations could be
detected on superclasses, specifically in the case where the
AnnotatedElementUtils.getAllAnnotationAttributes() method is invoked to
obtain multiple annotations of the same type (on the lowest level in the
class hierarchy), as is the case for @Profile and @Conditional.

This commit partially reverts these changes as follows:

 - All methods in AnnotatedElementUtils now set the
   traverseClassHierarchy to false, thereby effectively reverting the
   changes made in commit 1d30bf83.
   Note, however, that the changes made to AnnotationUtils remain in
   place.

 - Introduced tests in AnnotationMetadataTests that verify behavior
   present in Spring Framework 4.0.2 and earlier.

 - Updated tests in AnnotatedElementUtilsTests so that they pass against
   the reverted changes (i.e., align with the behavior present in Spring
   Framework 4.0.2 and earlier).

 - Refined Javadoc in AnnotationMetadata with regard to annotations
   being "present" vs. "defined".

 - Refined Javadoc in AnnotatedTypeMetadata.

Issue: SPR-11475, SPR-11595

Prior to this commit, Spring supported meta-annotation attribute
overrides in custom composed annotations with reflection-based
annotation processing but not with ASM-based annotation processing.

This commit ensures that meta-annotation attribute overrides are
supported in AnnotationMetadataReadingVisitor.getAnnotationAttributes().

Issue: SPR-11574

Fix ASM AnnotationAttributesReadingVisitor to correctly deal with
subclasses enums.

Issue: SPR-10914

Update AnnotationMetadata and MethodMetadata to extend from a new
AnnotatedTypeMetadata base interface containing the methods that are
common to both. Also introduce new getAllAnnotationAttributes methods
providing MultiValueMap access to both annotation and meta-annotation
attributes.

Existing classreading and standard implementations have been
refactored to support the new interface.

Prior to this commit many test utility classes and sample beans were
duplicated across projects. This was previously necessary due to the
fact that dependent test sources were not shared during a gradle
build. Since the introduction of the 'test-source-set-dependencies'
gradle plugin this is no longer the case.

This commit attempts to remove as much duplicate code as possible,
co-locating test utilities and beans in the most suitable project.
For example, test beans are now located in the 'spring-beans'
project.

Some of the duplicated code had started to drift apart when
modifications made in one project where not ported to others. All
changes have now been consolidated and when necessary existing tests
have been refactored to account for the differences.

Conflicts:
	spring-beans/src/test/java/org/springframework/beans/factory/ConcurrentBeanFactoryTests.java
	spring-beans/src/test/java/org/springframework/beans/factory/support/BeanFactoryGenericsTests.java
	spring-beans/src/test/java/org/springframework/beans/support/PagedListHolderTests.java

  find . -type f -name "*.java" -or -name "*.aj" | \
    xargs perl -p -i -e "s/[ \t]*$//g" {} \;

Issue: SPR-10127

Avoid Eclipse classpath conflicts between test versions of @Qualified
and @Autowired living in spring-core and actual versions living in
spring-beans.

This renaming more intuitively expresses the relationship between
subprojects and the JAR artifacts they produce.

Tracking history across these renames is possible, but it requires
use of the --follow flag to `git log`, for example

    $ git log spring-aop/src/main/java/org/springframework/aop/Advisor.java

will show history up until the renaming event, where

    $ git log --follow spring-aop/src/main/java/org/springframework/aop/Advisor.java

will show history for all changes to the file, before and after the
renaming.

See http://chrisbeams.com/git-diff-across-renamed-directories

 - Use recent Gradle 1.0-milestone-8 snapshot
 - Add initial cut of build.gradle able to compile/test all modules
 - Update .gitignore
 - Generate Gradle wrapper scripts
 - Remove all Eclipse metadata files
 - Temporarily @Ignore tests that do not pass under Gradle

AnnotationMetadata returns Class values by default (again), allowing for explicit retrieval of String class names where preferred (SPR-5827)

@Primary/@Lazy/@DependsOn supported as meta-annotations; @Bean supported as meta-annotation on factory methods as well

Initial cut of feature to create factory beans using the @FactoryBean annotation within a @Component

ASM-based AnnotationMetadata fully resolves class arguments and enums into Java types (SPR-5477, SPR-5479)