GenericApplicationContext and AbstractRefreshableApplicationContext
implementations now call DefaultListableBeanFactory.setSerializationId()
only upon successful refresh() instead of on instantiation of the
context, as was previously the case with GAC.

DLBF.setSerializationId() adds the beanFactory to the *static*
DLBF.serializableFactories map, and while calling close() on the
application context removes entries from that map, it does so only if
the context is currently active (i.e. refresh() has been called).

Also, cancelRefresh() has been overridden in GAC just as it has been
in ARAC to accomodate the possibility of a BeansException being thrown.
In this case, the beanFactory serializationId will be nulled out and
the beanFactory removed from the serializableFactories map.

The SerializableBeanFactoryMemoryLeakTests test case provides full
coverage of these scenarios.

SPR-7474 - AbstractXmlStreamReader getAttributeValue(String, String) does not handle null namespaceURI properly

All <section/> elements in beans.xml >=~ 500 lines have been broken out
into separate documents with DOCTYPE 'section'. This refactoring makes
working with these files much easier in wysiwyg editors (namely
oXygen Author).

For consistency, this same refactoring should be applied to all other
chapters much larger than 1500 lines, such as aop.xml (3861), mvc.xml
(3466), jdbc.xml (3042), and so on.

beans.xml and the new section files have also been formatted for
consistency and to avoid whitespace diffs as much as possible into the
future.

revised constructor argument caching for highly concurrent creation scenarios (follow-up to SPR-7423)

JavaDoc and reference docs now warn developers against interacting with
bean instances within BeanFactoryPostProcessor implementations in order
to avoid premature bean instantiation.

See SPR-7450 for an example of a third-party BFPP
(OAuthTokenLifecycleRegistryPostProcessor) prematurely instantiating
a FactoryBean instance, such that bean post-processing is bypassed
and autowired injection (via @Inject) never occurs.

consistent converting and escaping of label values (following AbstractMultiCheckedElementTag's SPR-7174)

WebDataBinder and @mvc request param binding detect and introspect MultipartFile arrays as well (SPR-2784)

Servlet/PortletContextResource inherit isReadable, contentLength and lastModified from AbstractFileResolvingResource

CommonsMultipartResolver cleans up all multipart files in case of multiple files for same name as well (SPR-2784)

WebDataBinder and @mvc request param binding detect and introspect MultipartFile arrays as well (SPR-2784)