@EnableTransactionManagement and co get detected on superclasses as well

Issue: SPR-10864
Polishing around @EnableTransactionManagement

Issue: SPR-10864
Synchronized cache creation on CacheManager

Issue: SPR-11132
XML namespace for configuring WebSocket, STOMP.

This commit describes the XML syntax with a XSD file for the websocket namespace.
XML examples are used for our testsuite.

Issue: SPR-11063
Add <websocket:handler-mappings/> XML configuration support

Issue: SPR-11063
Started implementing MessageBroker xml configuration.

Refactored common elements in ab abstract class.
Work in progress.

Issue: SPR-11063
Move message-broker xml config to separate package
WIP: stomp websockethandler strategy implementation
Refactor MessageHandler subscriptions
Add stomp-endpoint element parsing
Further updates to message broker xml config
Refactor XML websocket namespace

- websocket:handler-mappings is now websocket:handlers
- some external elements are now subelements

Issue: SPR-11063
Fix typo
WIP XML websocket namespace

- added bean definitions for messageConverter, messagingTemplate,
annotationMessageHandler
- register messageBroker (simple, noop or relay)
- refactor XML attribute names to lowercase and "-"

Issue: SPR-11063
Remove NoOpBroker - useless for XML configuration.
Register a UserDestinationMessageHandler and Polish
Add custom channels