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