INT-3142 Allow Merging of HTTP Message Converters

INT-3142: A flag to retain default converters when the user has customized messageconverters for HttpRequestHandlingController, HttpInboundGateway

* Introduced a new flag in the base class of HttpRequHttpRequestHandlingController, HttpInboundGateway - registerDefaultConverters
* Introduced a new attribute "register-default-converters" for inbound-channel-adapter and inbound-gateway to indicate if the default HttpMessageConverter's need to be registered
* Http namespace parser related changes to set the new flag
* Added additional tests to test the flag and the namespace parser related changes

Changes per feedback from Artem - additional javadoc comments, cleaned up tests

Updated: Setting the register-default-converters by default to false now, for backward compatibility reasons
Changed adapter name per feedback from Artem

Changed adapter name per feedback from Artem

Changed attribute name from register-default-converters to merge-with-default-converters

INT-3142: Atomic operation for messageConverters

'What's New' polishing

Polishing

Fix a few comments, error messages, docs, whitespace.
INT-2768 Add XSLT Transformer Factory Class Name

Add the ability to inject the class name of the xslt transformer
implementation.

https://jira.springsource.org/browse/INT-2768

-add @author to java docs
-updat copywrite year to current year

add new test and check for class name that it exists.

-fix xslt payload transformer and test for unknown class name, will
now default to the jre default transformer.
INT-2768: Add BeanClassLoaderAware
INT-2768 Polishing - Docs, White Space

Add what's new; fix white space in test case.
Merge pull request #897 from mbazos/INT-2768

* INT-2768:
  INT-2768 Polishing - Docs, White Space
  INT-2768: Add BeanClassLoaderAware
  INT-2768 Add XSLT Transformer Factory Class Name
INT-2312: HTTP RequestMapping support

The general idea to use Spring-MVC as much as possible.

* introduce `RequestMapping`, `IntegrationRequestMappingHandlerMapping`
* introduce XSD nested element `<request-mapping>` for HTTP Inbound Endpoints
* introduce `inboundCommonAttributes` XSD attributeGroup for HTTP Inbound Endpoints
* introduce `IntegrationNamespaceUtils#createExpressionDefIfAttributeDefined` & `IntegrationNamespaceUtils#createDirectChannel`
* remove deprecated `name` attribute
* remove `UriPathHandlerMapping` as superseded by `IntegrationRequestMappingHandlerMapping`

JIRA: https://jira.springsource.org/browse/INT-2312, https://jira.springsource.org/browse/INT-2619
INT-2528: Remove deprecations in HTTP module

JIRA: https://jira.springsource.org/browse/INT-2528
INT-2312: Doc for `<request-mapping>`

* Add description to Reference Manual about `<request-mapping>`
* Additional doc polishing
* Add additional test for `<request-mapping>`
* Polishing according PR's comments
INT-2312: 'What's new' and http doc polishing
INT-2312: Add Jackson 2 support for HTTP-inbound
INT-2312: Rebase polishing
INT-2312: Review & email discussion polishing

* Make `RequestMapping` public
* Introduce `HttpContextUtils` and move `HANDLER_MAPPING_BEAN_NAME` to it
* Revert and deprecate public API
* Improve JavaDocs
* Improve Reference Manual
* Rework `IntegrationRequestMappingHandlerMapping` according to email discussion
INT-2312: Polishing after rebase
INT-2312: Docs polishing and tests
Using Jackson 2 HttpMessageConverter if Jackson 2 is available in classpath
Apply Biju Kunjummen commit
INT-2312: Polishing after rebase