Fix detection of the @SendTo annotation

Previously, the default reply destination could not be discovered if the
@JmsListener annotation was placed on a bean that is eligible for
proxying as the proxy method is used internally and does not reveal
an annotation placed on the implementation.

This commit makes sure to resolve the most specific method when
searching that annotation.

Issue: SPR-12513
Fix and polish Javadoc for JpaTransactionManager
Update unprocessableEntity to allow body

Issue: SPR-12515
Fix JavaDoc in TestExecutionListener regarding Ordered
Next Development Version
Remove outdated reference to Spring Modules
Work-around for Eclipse bug regarding EnumSets

This commit introduces superfluous casts in CollectionFactory to
address a bug in Eclipse 4.4.1 that prevents the code from compiling
within Eclipse. Specifically, without these casts Eclipse displays the
following error for use of the EnumSet.copyOf() and EnumSet.noneOf()
methods:

Type mismatch: cannot convert from EnumSet<Enum<Enum<E>>> to
Collection<E>
Suppress "rawtypes" warnings in CollectionFactory

This commit also adds links to the newly created Eclipse bug that was
raised for this issue.
Use public AssumptionViolatedException in Assume

JUnit 4.12 created a 'public' version of the previously 'internal'
AssumptionViolatedException.

This commit upgrades Spring's Assume class to use this new public
version.
Polish reference manual

This commit put more emphasis on Spring Boot in the
"Getting Started" section, and update some outdated excerpts.
List Spring Framework artifacts in the reference manual

Issue: SPR-12517
Polish Spring Framework Artifacts table

Issue: SPR-12517
Improve performance of generateKey

Only compute the error message to display when the generated key is
actually null instead of using Assert.notNull as the cache operation
'toString()' method is non trivial and gets computed regardless of the
result.

Issue: SPR-12527
Polish grammar and wording in the reference manual
Improve error handling in CollectionFactory

This commit improves error handling in CollectionFactory by asserting
preconditions.

In addition, this commit introduces ConnectionFactoryTests.
Cover maps & more collections in CollectionFactoryTests
Demonstrate that the CollectionFactory API is not type-safe

This commit introduces test methods in CollectionFactoryTests that
demonstrate how the APIs for createApproximateCollection() and
createApproximateMap() are not type-safe, specifically regarding the use
of generics, raw types, and casting.
Create empty EnumSets & EnumMaps in CollectionFactory

SPR-12483 introduced automatic type conversion support for EnumSet and
EnumMap. However, the corresponding changes in CollectionFactory
contradict the existing contract for the "create approximate" methods
by creating a copy of the supplied set or map, thereby potentially
including elements in the returned collection when the returned
collection should in fact be empty.

This commit addresses this issue by ensuring that the collections
returned by createApproximateCollection() and createApproximateMap()
are always empty.

Furthermore, this commit improves the Javadoc throughout the
CollectionFactory class.

Issue: SPR-12533
Demonstrate that the CollectionFactory API is not type-safe

This commit introduces test methods in CollectionFactoryTests that
demonstrate how the APIs for createCollection() and createMap() are not
type-safe, specifically regarding the use of generics, raw types, and
casting.
Upgrade Jetty to 9.2.6.v20141205