Add SimpleMessageConverter
Add new features on @ControllerAdvice

Prior to this commit, @ControllerAdvice annotated beans would
assist all known Controllers, by applying @ExceptionHandler,
@InitBinder, and @ModelAttribute.

This commit updates the @ControllerAdvice annotation,
which accepts now base package names, assignableTypes,
annotations and basePackageClasses.

If attributes are set, only Controllers that match those
selectors will be assisted by the annotated class.
This commit does not change the default behavior when
no value is set, i.e. @ControllerAdvice().

Issue: SPR-10222
Polish ControllerAdvice selectors

Issue: SPR-10222
Merge pull request #380 from bclozel/SPR-10222
Allow TypeDescriptor create with null generics

Restore the ability to create a TypeDescriptor for a collection or
map where the generics may be null.

Issue: SPR-11006
Upgrade json-path to 0.9.0 version

This version fixed bugs and improved performance.
New features: "select multiple attributes" and
"Array operations and slicing improved" (a new example
has been added in tests to reflect that).

See https://github.com/jayway/JsonPath/blob/master/README

Issue: SPR-10990
Support @PathVariable in annotated message handling methods

Prior to this commit, @SubscribeEvent @UnsubscribeEvent and
@MessageMapping annotated message handling methods
could only match a strict message destination.

This commit adds a @PathVariable annotation and
updates the message matching/handling process, since
message handling methods can now match PathMatcher-like
destinations and get path variables injected in parameters.

Issue: SPR-10949
Polish AnnotationMethodMessageHandler and annotations
Remove @UnsubscribeEvent

The STOMP UNSUBSCRIBE message does not have a destination header so
there is no obvious simple way to do a mapping and the need for it
is not clear yet.
Improve GenericMessage.toString()

Restore pringing the payload first and headers second as it has been in
SI but also handle specifically the case where the body is a byte array
to minimize unnecessary "noise" that causes otherwise for STOMP msgs.
Increase timeout for Stomp integration tests
Relax JavaBean rules for SpEL property access

Relax the method search algorithm used by `ReflectivePropertyAccessor`
to include methods of the form `getXY()` for properties of the form
`xy`.

Although the JavaBean specification indicates that a property `xy`
should use the accessors `getxY()` and `setxY()`, in practice many
developers choose to have an uppercase first character. The
`ReflectivePropertyAccessor` will now consider these style methods if
the traditional conventions fail to find a match.

Issue: SPR-10716
Skip convert to Object from TypeConverterDelegate

Update TypeConverterDelegate to bypass conversion when the target type
is Object.class. Prior to this commit converting a single element array
to an Object would result in the element being returned, rather than
the array itself.

Issue: SPR-10996
Propagate EvaluationContext from LiteralExpression

Update getValue(EvaluationContext context, Object rootObject,
Class<T> desiredResultType) to propagate the EvaluationContext to
ExpressionUtils.

Issue: SPR-10953
Assert context uniqueness against merged config

Prior to this commit, the uniqueness check for @ContextConfiguration
attributes within a @ContextHierarchy was performed at a single test
class level instead of against the merged configuration for all test
class levels in the test class hierarchy.

This commit addresses this issue by moving the uniqueness check
algorithm from resolveContextHierarchyAttributes() to
buildContextHierarchyMap() within ContextLoaderUtils.

Issue: SPR-10997
Add targetIsClass to SpEL property cache key

Update the `CacheKey` class used by `ReflectivePropertyAccessor` to
include if the target object is class. The prevents an incorrect cache
hit from being returned when a property with the same name is read on
both an object and its class. For example:

	#{class.name}
	#{name}

Issue: SPR-10486
Multicaster support for events with null source

Update `AbstractApplicationEventMulticaster` to support `EventObjects`
with a null source (which can happen if they have been serialized).

Issue: SPR-10945
Consistent ordering for @PropertySource locations

Ensure that property source locations are processed in the same order
regardless if the 'name' attribute is set or not.

Prior to this commit multiple locations from a `@PropertySource` with
a name were added to a `CompositePropertySource` in such a way that
the first location would take precedence. This has now been reversed
for consistence with unnamed `@PropertySource`s

Issue: SPR-10820
Polish (minor)
Introduced MvcUriComponentsBuilder to create URIs pointing to controller methods.

MvcUriComponentsBuilder allows creating URIs that point to Spring MVC
controller methods annotated with @RequestMapping. It builds them by
exposing a mock method invocation API similar to Mockito, records the
method invocations and thus builds up the URI by inspecting the mapping
annotations and the parameters handed into the method invocations.

Introduced a new SPI UriComponentsContributor that should be implemented 
by HandlerMethodArgumentResolvers that actually contribute path segments 
or query parameters to a URI. While the newly introduced 
MvcUriComponentsBuilder looks up those UriComponentsContributor instances 
from the MVC configuration.

The MvcUriComponentsBuilderFactory (name to be discussed - MvcUris maybe?) 
prevents the multiple lookups by keeping the UriComponentsBuilder 
instances in an instance variable. So an instance of the factory could 
be exposed as Spring bean or through a HandlerMethodArgumentResolver to 
be injected into Controller methods.

Issue: SPR-10665, SPR-8826