Issue: SPR-11437

Issue: SPR-11496, SPR-11525

In Tiles v3 integration, underscores in filenames are
intended to identify the definition locale. This behavior
is now documented in order to avoid unexpected results
with filenames like tiles_definitions.xml.

This commit also updates Tiles v2 references to Tiles v3
in the Spring reference documentation.

Issue: SPR-11491

This commit updates reference documentation in order
to specify that ServletServerContainerFactoryBean is for
server side use and WebSocketContainerFactoryBean
for client side use.

Issue: SPR-11565

Issue: SPR-11432

Issue: SPR-11495

Issue: SPR-11486

Issue: SPR-11500

The Servlet API does not provide notifications when a client
disconnects, see see https://java.net/jira/browse/SERVLET_SPEC-44.
Therefore network IO failures may occur simply because a client has
gone away. Before this change that could fill logs with unnecessary
stack traces.

After this change we make a best effort to identify such network
failures, on a per-server basis (tested with Jetty, Tomcat, Glassfish,
and WildFly), and log them under a separate log category.

A simple one-line message is logged at DEBUG level (i.e. no stack trace)
while a full stack trace is shown at TRACE level.

Issue: SPR-11438

 - "__ `text`__" --> "__`text`__"

 - "`text` s" --> "`text`s"

The breakout box named "Constructor-based or setter-based DI?" in the
reference manual currently recommends the use of setter injection.

This commit refines this text to align with current best practices and
now favors constructor injection over setter injection.

Issue: SPR-11459

Also removed outdated Struts references and made use of 'javadocs' term consistent.

Issue: SPR-11473

Clarify ability to use @MessageMapping methods on both @Controller as
well as @RestController.

Add section on configuring connections (including credentials) to the
message broker and clarify the use of the login/passcode headerers of
the STOMP CONNECT frame.

Add note on when to add the reactor-tcp dependency.

Issue: SPR-11464, SPR-11436, SPR-11449

Issue: SPR-11425

Before this change, issues surrounding the use of @Controller's in
combination with AOP proxying, resulted in an IllegalArgumentException
when trying to invoke the controller method.

This change detects such cases proactively and reports them with a
clear recommendation to use class-based proxying when it comes to
@Controller's. This is the most optimcal approach for controllers
in many respects, also allows @mvc annotations to remain on the
class.

The documentation has also been updated to have a specific section
on @Controller's and AOP proxying providing the same advice.

Issue:SPR-11281

Issue: SPR-11404

This commit fixes some formatting issues in the 'TestContext Framework
support classes' section of the reference manual that were introduced
in the conversion from DocBook to AsciiDoc.

Update reference documentation to make it clearer that only
`spring-core` has a direct dependency on `commons-logging`.

Also reference the 'empty jar' alternative option as described in
the SLF4J FAQ.

Issue: SPR-11023

Prior to this commit, it was not clear how to enable the support of matrix
variables in the mvc namespace. As the feature is disabled by default, added
something to highlight the part that explains how to configure it

Issue: SPR-11331

Issue: SPR-11129

Issue: SPR-11311

Issue: SPR-11266

Issue: SPR-8182
Issue: SPR-11243
Issue: SPR-11292
Issue: SPR-11318

Issue: SPR-11256

Issue: SPR-11301

Better integrated explanation of the 'default' profile with both XML
and Java config examples showing the same thing.

Issue: SPR-11256

- Remove formatting that interferes with code highlighting
- Fix some XML syntax issues
- Added missing punctuation

Issue: SPR-11280