Fix minor issue in WebSocketHttpRequestHandler

Issue: SPR-10721
Cache constructor instance in WebAsyncUtils

Issue: SPR-10673
Enable asyncSupported flag in Spring Test MVC

Also remove Servlet 3 bridge classes no longer needed since Spring
Framework 4 compiles with the Servlet 3 API. That means applications
may need to run tests with the Servlet 3 API jar although
technically they don't have to run with that in production.
Fix bug in SockJS JsonpTransportHandler

Issue: SPR-10621
Fix issue with xpath assertions in Spring Test MVC

Issue: SPR-10704
Fix issue in ContentNeogitatingViewResolver

The following commit in 3.2.3 had a side effect on CNVR:
https://github.com/SpringSource/spring-framework/commit/aaded7e30b06cc70a354856a2288acd04045b673

It appears that CNVR doesn't treat a request for "*/*" differently
from a request that does not request content types. Both should be
interpreted as "any content type is acceptable". This fix ensures
that CNVR treats these two cases the same way.

Issue: SPR-10683
Polish concurrency in UserSessionResolver impl
Added 'processExternalEntities' to JAXB2Marshaller

Added 'processExternalEntities' property to the JAXB2Marshaller, which
indicates whether external XML entities are processed when
unmarshalling.

Default is false, meaning that external entities are not resolved.
Processing of external entities will only be enabled/disabled when the
Source} passed to #unmarshal(Source) is a SAXSource or StreamSource. It
has no effect for DOMSource or StAXSource instances.
Resolve ${} placeholders in @ImportResource

Update ConfigurationClassParser to resolve any ${} placeholders from
@ImportResource values.

Issue: SPR-10686
Turn down logging in DefaultListableBeanFactory

Reduce INFO level startup logging to DEBUG

Issue: SPR-10758
Fixed potential NPE in SharedEntityManagerCreator

Fix SharedEntityManagerCreator.createSharedEntityManager to correctly
forward an empty array in case that EntityManagerFactoryInfo returns
null from getEntityManagerInterface().

Previously the var-args invocation had turned null into an array with
a null value which caused a NullPointerException in the call to
Proxy.newProxyInstance() further down the call stack.

Issue: SPR-10678
Merge pull request #303 from olivergierke/SPR-10678

# By Oliver Gierke
* SPR-10678:
  Fixed potential NPE in SharedEntityManagerCreator
Add Java SE Javadoc links

Issue: SPR-10587
Revise UserSessionResolver to UserQueueSuffixResolver

The resolver for /user/{username} prefixed destinations is now
more explicitly designed to store queue suffixes rather than session
id's, which is what we happen to use as queue suffixes.

This allows something other than the sessionId to be used without
having to change many places. It also enables applications to
construct destinations with user-specific queue suffixes without
making assumptions about what's used for queue suffixes. For
example a controller may construct a map with subscription destinations
and send that down to the client.
Fix issue in MappingJacksonJsonView

Issue: SPR-10752
Replace assert w/ warning in ResourceHttpRequestHandl.

Issue: SPR-9186
Make the JSON prefix used in converters configurable

Issue: SPR-10627
Add MemorySafeUndeclaredThrowableStrategy

Port the latest unreleased UndeclaredThrowableStrategy implementation
from cglib to fix a memory-leak present in v3.

Issue: SPR-10709
Add MessageMethodArumentResolver
Add MessageHandler destination prefix checks