Currently the Spring TestContext Framework looks up a
PlatformTransactionManager bean named "transactionManager". The exact
name of the bean can be overridden via @TransactionConfiguration or
@Transactional; however, the bean will always be looked up 'by name'.

The TransactionManagementConfigurer interface that was introduced in
Spring 3.1 provides a programmatic approach to specifying the
PlatformTransactionManager bean to be used for annotation-driven
transaction management, and that bean is not required to be named
"transactionManager". However, as of Spring 3.1.2, using the
TransactionManagementConfigurer on a @Configuration class has no effect
on how the TestContext framework looks up the transaction manager.
Consequently, if an explicit name or qualifier has not been specified,
the bean must be named "transactionManager" in order for a transactional
integration test to work.

This commit addresses this issue by refactoring the
TransactionalTestExecutionListener so that it looks up and delegates to
a single TransactionManagementConfigurer as part of the algorithm for
determining the transaction manager.

Issue: SPR-9604

TransactionalTestExecutionListener currently requires that the
PlatformTransactionManager bean be named "transactionManager" by
default. Otherwise, the bean name can only be overridden via the
transactionManager attribute of @TransactionConfiguration or the value
attribute of @Transactional.

However, if there is only a single PlatformTransactionManager in the
test's ApplicationContext, then the requirement to specify the exact
name of that bean (or to name it exactly "transactionManager") is often
superfluous.

This commit addresses this issue by refactoring the
TransactionalTestExecutionListener so that it is comparable to the
algorithm for determining the transaction manager used in
TransactionAspectSupport for "production" code. Specifically, the TTEL
now uses the following algorithm to retrieve the transaction manager.

 - look up by type and qualifier from @Transactional
 - else, look up by type and explicit name from
   @TransactionConfiguration
 - else, look up single bean by type
 - else, look up by type and default name from @TransactionConfiguration

Issue: SPR-9645

Commit 096693c4 refactored and
deprecated TransactionAspectUtils, moving its #qualifiedBeanOfType
and related methods into BeanFactoryUtils. This created a package cycle
between beans.factory and beans.factory.annotation due to use of the
beans.factory.annotation.Qualifier annotation in these methods.

This commit breaks the package cycle by introducing
beans.factory.annotation.BeanFactoryAnnotationUtils and moving these
@Qualifier-related methods to it. It is intentionally similar in name
and style to the familiar BeanFactoryUtils class for purposes of
discoverability.

There are no backward-compatibilty concerns associated with this change
as the cycle was introduced, caught and now fixed before a release.

Issue: SPR-6847

TransactionAspectUtils contains a number of methods useful in
retrieving a bean by type+qualifier. These methods are functionally
general-purpose save for the hard coding of PlatformTransactionManager
class literals throughout.

This commit generifies these methods and moves them into
BeanFactoryUtils primarily in anticipation of their use by async method
execution interceptors and aspects when performing lookups for qualified
executor beans e.g. via @Async("qualifier").

The public API of TransactionAspectUtils remains backward compatible;
all methods within have been deprecated, and all calls to those methods
throughout the framework refactored to use the new BeanFactoryUtils
variants instead.

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

[SPR-5315][SPR-5699] Reverted changes to TransactionalTestExecutionListener: transactions are no longer automatically flushed before rolling back.

added "flush()" method to TransactionStatus and TransactionSynchronization interfaces; test context manager automatically flushes transactions before rolling back; general polishing of transaction management code