Convert TestContext to interface & default impl

Since the Spring TestContext Framework was introduced in Spring
Framework 2.5, the TestContext class has always been a public class
with package private constructors. The visibility of TestContext's
constructor and methods was intentionally limited in order to hide the
implementation details of the context cache, etc. However, this fact
has made it difficult (if not impossible) to unit test custom
TestExecutionListener implementations.

This commit addresses this issue by converting TestContext into a
public interface with a package private DefaultTestContext
implementation. This enables unit testing of any components that depend
on a TestContext (e.g., TestExecutionListeners) while at the same time
preserving the encapsulation of the inner workings of the TestContext
implementation with regard to context loading and caching.

Issue: SPR-7692
Proper matching of raw generic types and generically typed factory methods

Also optimized getTypeForFactoryMethod's implementation for non-generic factory methods, and reduced calls to getResolvedFactoryMethod in order to avoid repeated synchronization.

Issue: SPR-11034
Polishing
Added further tests for raw matching of generic types

Issue: SPR-11034
Issue: SPR-11004
Fixed resolveReturnTypeForFactoryMethod to unwrap TypedStringValue

XML-defined arguments values are initially turned into TypedStringValue wrappers. If we encounter an unresolved argument, we need to unwrap such a TypedStringValue and then try to treat its content as a class name.

Issue: SPR-11034
Polishing
Replace use of jdk 1.8 api
Aligned with refinements in 3.2.x branch

Issue: SPR-11034
Provide meta-annotation support in the TCF

Spring 3.0 already allows component stereotypes to be used in a
meta-annotation fashion, for example by creating a custom
@TransactionalService stereotype annotation which combines
@Transactional and @Service in a single, reusable, application-specific
annotation. However, the Spring TestContext Framework (TCF) currently
does not provide any support for test-related annotations to be used as
meta-annotations.

This commit overhauls the TCF with regard to how annotations are
retrieved and adds explicit support for the following annotations to be
used as meta-annotations in conjunction with the TCF.

- @ContextConfiguration
- @ContextHierarchy
- @ActiveProfiles
- @DirtiesContext
- @IfProfileValue
- @ProfileValueSourceConfiguration
- @BeforeTransaction
- @AfterTransaction
- @TransactionConfiguration
- @Rollback
- @TestExecutionListeners
- @Repeat
- @Timed
- @WebAppConfiguration

Note that meta-annotation support for @Transactional was already
available prior to this commit.

The following is a summary of the major changes included in this commit.

- Now using AnnotationUtils.getAnnotation() instead of
  Class.getAnnotation() where appropriate in the TestContext Framework.
- Now using AnnotationUtils.findAnnotation() instead of
  Class.isAnnotationPresent() where appropriate in the TestContext
  Framework.
- Introduced findAnnotationPrefersInteracesOverLocalMetaAnnotations() in
  AnnotationUtilsTests in order to verify the status quo.
- AnnotationUtils.findAnnotationDeclaringClass() and
  AnnotationUtils.findAnnotationDeclaringClassForTypes() now support
  meta annotations.
- Introduced MetaAnnotationUtils and AnnotationDescriptor in the
  spring-test module.
- Introduced UntypedAnnotationDescriptor in MetaAnnotationUtils.
- Introduced findAnnotationDescriptorForTypes() in MetaAnnotationUtils.
- ContextLoaderUtils now uses MetaAnnotationUtils for looking up
  @ActiveProfiles as a potential meta-annotation.
- TestContextManager now uses MetaAnnotationUtils for looking up
  @TestExecutionListeners as a potential meta-annotation.
- DirtiesContextTestExecutionListener now uses AnnotationUtils for
  looking up @DirtiesContext as a potential meta-annotation.
- Introduced DirtiesContextTestExecutionListenerTests.
- ProfileValueUtils now uses AnnotationUtils for looking up
  @IfProfileValue and @ProfileValueSourceConfiguration as potential
  meta-annotations.
- @BeforeTransaction and @AfterTransaction now support ANNOTATION_TYPE
  as a target, allowing them to be used as meta-annotations.
- TransactionalTestExecutionListener now uses AnnotationUtils for
  looking up @BeforeTransaction, @AfterTransaction, @Rollback, and
  @TransactionConfiguration as potential meta-annotations.
- Introduced TransactionalTestExecutionListenerTests.
- @Repeat and @Timed now support ANNOTATION_TYPE as a target, allowing
  them to be used as meta-annotations.
- SpringJUnit4ClassRunner now uses AnnotationUtils for looking up
  @Repeat and @Timed as potential meta-annotations.
- Moved all remaining logic for building the MergedContextConfiguration
  from the DefaultTestContext constructor to
  ContextLoaderUtils.buildMergedContextConfiguration().
- Verified meta-annotation support for @WebAppConfiguration and
  @ContextConfiguration.

Issue: SPR-7827
Merge pull request #393 from sbrannen/SPR-7827

* SPR-7827:
  Provide meta-annotation support in the TCF
Relocate test class to src/test/java folder
Renamed @WebTests to @WebTest

@WebTests has been renamed to @WebTest so that the Gradle build does not
attempt to run it as a JUnit test.
Defensive handling of exceptions during factory method type checking

Also using ClassUtils.forName in AutowireUtils now in order to accept all common class name formats.

Issue: SPR-11034
Ignore .idea
Polish BeanMethodPolymorphismTests

Polish BeanMethodPolymorphismTests and add @Ignored failing test
for SPR-10988.

Issue: SPR-10988
Add support for WebSocket Protocol Extensions

This commits adds simple, overridable WebSocket Extension
filtering during the handshake phase and adds that
information in the WebSocket session.

The actual WebSocket Extension negotiation happens
within the server implementation (Glassfish, Jetty, Tomcat...),
so one can only remove requested extensions from
the list provided by the WebSocket client.

See RFC6455 Section 9.

Issue: SPR-10843
Update WebSocket extensions change

- add WebSocketHttpHeaders
- client-side support for WebSocket extensions
- DefaultHandshakeHandler updates
- replace use of ServletAttributes in JettyRequestUpgradeStratey
- upgrade spring-web to jetty 9.0.5
Merge pull request #392 from bclozel/SPR-10843
Polish MvcUriComponentsBuilder
Workaround Javadoc bug with JDK 8 (b112+)

Remove Javadoc linkplain to ExceptionHandler#value() from
AnnotationMethodHandlerExceptionResolver to work around JDK
Javadoc bug 9007707.