Raised all dependencies to latest possible maintenance releases; introduced additional library version variables; consistently grouped dependency scopes

This commit introduces transactional integration tests executing
against both JUnit and TestNG in the TestContext framework (TCF) using
@TransactionAttribute in EJBs instead of Spring’s @Transactional
annotation.

These tests disprove the claims raised in SPR-6132 by demonstrating that
transaction support in the TCF works as expected when a transactional
EJB method that is configured with TransactionAttribute.REQUIRES_NEW is
invoked. Specifically:

 - The transaction managed by the TCF is suspended while such an EJB
   method is invoked.
 - Any work performed within the new transaction for the EJB method is
   committed after the method invocation completes.
 - The transaction managed by the TCF is resumed and subsequently
   either rolled back or committed as necessary based on the
   configuration of @Rollback and @TransactionConfiguration.

The configuration for the JUnit-based tests is straightforward and self
explanatory; however, the configuration for the TestNG tests is less
intuitive.

In order for the TCF to function properly, the developer must ensure
that test methods within a given TestNG test (whether defined locally,
in a superclass, or somewhere else in the suite) are executed in the
proper order. In a stand-alone test class this is straightforward;
however, in a test class hierarchy (or test suite) with dependent
methods, it is necessary to configure TestNG so that all methods within
an individual test are executed in isolation from test methods in other
tests. This can be achieved by configuring a test class to run in its
own uniquely identified suite (e.g., by annotating each concrete
TestNG-based test class with @test(suiteName = "< Some Unique Suite
Name >")).

For example, without specifying a unique suite name for the TestNG
tests introduced in this commit, test methods will be executed in the
following (incorrect) order:

 - CommitForRequiredEjbTxDaoTestNGTests.test1InitialState()
 - CommitForRequiresNewEjbTxDaoTestNGTests.test1InitialState()
 - RollbackForRequiresNewEjbTxDaoTestNGTests.test1InitialState()
 - RollbackForRequiredEjbTxDaoTestNGTests.test1InitialState()
 - CommitForRequiredEjbTxDaoTestNGTests.test2IncrementCount1()

The reason for this ordering is that test2IncrementCount1() depends on
test1InitialState(); however, the intention of the developer is that
the tests for an individual test class are independent of those in
other test classes. So by specifying unique suite names for each test
class, the following (correct) ordering is achieved:

 - RollbackForRequiresNewEjbTxDaoTestNGTests.test1InitialState()
 - RollbackForRequiresNewEjbTxDaoTestNGTests.test2IncrementCount1()
 - RollbackForRequiresNewEjbTxDaoTestNGTests.test3IncrementCount2()
 - CommitForRequiredEjbTxDaoTestNGTests.test1InitialState()
 - CommitForRequiredEjbTxDaoTestNGTests.test2IncrementCount1()
 - CommitForRequiredEjbTxDaoTestNGTests.test3IncrementCount2()
 - RollbackForRequiredEjbTxDaoTestNGTests.test1InitialState()
 - RollbackForRequiredEjbTxDaoTestNGTests.test2IncrementCount1()
 - RollbackForRequiredEjbTxDaoTestNGTests.test3IncrementCount2()
 - CommitForRequiresNewEjbTxDaoTestNGTests.test1InitialState()
 - CommitForRequiresNewEjbTxDaoTestNGTests.test2IncrementCount1()
 - CommitForRequiresNewEjbTxDaoTestNGTests.test3IncrementCount2()

See the JIRA issue for more detailed log output.

Furthermore, @DirtiesContext(classMode = ClassMode.AFTER_CLASS) has
been used in both the JUnit and TestNG tests introduced in this commit
in order to ensure that the in-memory database is reinitialized between
each test class.

Issue: SPR-6132

Prior to this commit TestNG tests would only be executed by the Gradle
build if they were located in the “testng” package. Tests in subpackages
would therefore be omitted from the build.

This commit ensures that all TestNG classes in the “testng” package and
any of its subpackages are executed in the Gradle build.

Furthermore, this commit ensures that the JUnit-based
FailingBeforeAndAfterMethodsTests test class is executed along with the
other JUnit tests even though it resides under the “testng” package.

Issue: SPR-11338

Upgrade to the latest release of jexcelapi and work-around the
ArrayIndexOutOfBounds test exception on *nix machines.

Issue: SPR-11334

JExcelAPI 2.6.12 appears to be causing ArrayIndexOutOfBoundsException
with the build. Rolling back to the earlier version for now

Issue: SPR-11273

Issue: SPR-11237

The Java and XML config for STOMP WebSocket applications now supports
configuring message converters.

Issue: SPR-11184

In sync with our Tiles3 TilesContainer implementation now, as far as possible.

Issue: SPR-11285

Issue: SPR-11226

This change involves a general upgrade to Jackson 2.3 in our build.

Issue: SPR-11261

Issue: SPR-10469

Also completing 4.0's consistency efforts between Spring's cache adapters.

Add 'spring-framework-bom' meta-project that contains the other projects
in a dependencyManagement section.

Issue: SPR-11138

This commit adds an XML namespace equivalent of @EnableWebSocket and
@EnableWebSocketMessageBroker. Those are <websocket:handlers> and
<websocket:message-broker> respectively.

Examples can be found in the test suite.

This commit also alters the way MessageHandler's subscribe to their
respective MessageChannel's of interest. Rather than performing the
subscriptions in configuration code, the message channels are now
passed into MessageHandler's so they can subscribe themselves on
startup.

Issue: SPR-11063

Fix remaining Java compiler warnings, mainly around missing
generics or deprecated code.

Also add the `-Werror` compiler option to ensure that any future
warnings will fail the build.

Issue: SPR-11064

Before this change spring-messaging contained a few WebSocket-related
classes including WebSocket sub-protocol support for STOMP as well
as @EnableWebSocketMessageBroker and related configuration classes.

After this change those classes are located in the spring-websocket
module under org.springframework.web.socket.messaging.

This means the following classes in application configuration must
have their packages updated:

org.springframework.web.socket.messaging.config.EnableWebSocketMessageBroker
org.springframework.web.socket.messaging.config.StompEndpointRegistry
org.springframework.web.socket.messaging.config.WebSocketMessageBrokerConfigurer

MessageBrokerConfigurer has been renamed to MessageBrokerRegistry and
is also located in the above package.

Replace `hsqldb:hsqldb:1.8.0.10` with `org.hsqldb:hsqldb:2.3.1` and
fix breaking tests.

Issue: SPR-10947

As of Gradle 1.8, ‘testReport true’ is deprecated. Thus in order to
generate TestNG reports alongside JUnit reports with Gradle 2.0 and
beyond, we are now using:

  getReports().getHtml().setEnabled(true)

Update InstrumentationSavingAgent to allow it to be used with the
Attach API

Issue: SPR-11083

Issue: SPR-11099

Generate docbook xml from the asciidoc reference guide and use the
docbook-reference-plugin to generate HTML (single and multi-page) and
PDF documentation.

Issue: SPR-11096

With spring-test compiling against Servlet 3.0 it is no longer required
to compile Spring MVC Test sources separately (from spring-test).

This commit migrates to asciidoctor to ease writing documentation.

Issues: SPR-10960

Upgraded to Apache HttpComponents HttpClient 4.3.1 and HttpAsyncClient 4.0 GA, as well as Jackson 2.2.2

Issue: SPR-11014