Issue: SPR-12297

Issue: SPR-12292

Issue: SPR-12285

Prior to this commit, the ResolvableType static cache was holding a lot
of duplicates for simple types. We are using too much metadata to compute
the key when the class has no generic information. so setFoo(String foo)
and setBar(String bar) would result in two entries in the cache because
the TypeProvider is different. On a very simple application 65% of the
entries in the cache were duplicate.

When the type is a Class with no generic information, the ResolvableType
instance is a simple wrapper around it so we might just as well not cache
it at all as the cost of finding it back from the cache is higher than
creating that simple wrapper.

This commit adds an explicit check; if the type is a simple Class we just
return a "resolved" ResolvableType instance for it. On a few test cases,
this reduces the size of the cache by 85%

Issue: SPR-12275

Prior to this commit, `AntPathMatcher.extractPathWithinPattern` would
not process correctly `**` patterns and would only match *one* path
segment in the given path.

This commit changes `extractPathWithinPattern` to allow multiple path
segments to be matched against a single `**` pattern segment.

Issue: SPR-10515

Issue: SPR-12255

Issue: SPR-12224

Issue: SPR-12231

Update PathMatchingResourcePatternResolver to include additional
protected methods that can be used by subclasses to optimize which
JARs are searched.

Issue: SPR-12231

Optimize ReflectionUtils.isCglibRenamedMethod by removing the regular
expression.

Issue: SPR-12227

Update SystemEnvironmentPropertySource to attempt optimized Map lookups
first, and only fall-back to the defensive SecurityManager safe-mode
if these fail.

Issue: SPR-12224

SystemEnvironmentPropertySource uses regular property names check instead of optimized Map lookup (for defensiveness in SecurityManager scenarios)

Issue: SPR-12224

Improve the performance of MapPropertySource by directly implementing
the containsProperty property.

Issue: SPR-12224

Issue: SPR-12181

Issue: SPR-12182

Per the Javadoc for the SocketUtils() constructor, SocketUtils can be
instantiated as a Spring Bean in XML configuration files; however,
SocketUtils is currently abstract which prevents such usage.

This commit removes the 'abstract' declaration thereby allowing
SocketUtils to be instantiated as a Spring bean.

Issue: SPR-12169

Issue: SPR-11310
Issue: SPR-10548

Prior to this commit, when there was a lot of entries in the
ResolvableType.cache HashMap, getting a simple value could
take a lot of time due to a lot of calls to ResolvableType.equals().
ResolvableType.equals() used this.type, getSource(),
this.variableResolver.getSource() and this.componentType, but
ResolvableType.hashCode() used only this.type.

With this commit, ResolvableType.hashCode() now uses the same
fields than ResolvableType.equals().

Performance on the spring-resolvabletype-benchmark project:
 - 8000 us before this commit
 - 120 us with this commit

Issue: SPR-12122

Revised ResourcePropertySource in order to avoid ConfigurationClassProcessor's AnnotationPropertySource subclass

Issue: SPR-12115

Rework the @PropertySource parsing logic recently changed in commit
7c608886 to deal with the same source appearing on a @Configuration
class and an @Import class.

Processing now occurs in a single sweep, with any previously added
sources being converted to a CompositePropertySource.

Issue: SPR-12115

PropertySource implementations perform conversion to String arrays via StringUtils (getting rid of EMPTY_NAMES_ARRAY)

Issue: SPR-12095

Prior to this commit, there was no declarative mechanism for a custom
TestExecutionListener to be registered as a default
TestExecutionListener.

This commit introduces support for discovering default
TestExecutionListener implementations via the SpringFactoriesLoader
mechanism. Specifically, the spring-test module declares all core
default TestExecutionListeners under the
org.springframework.test.context.TestExecutionListener key in its
META-INF/spring.factories properties file, and third-party frameworks
and developers can contribute to the list of default
TestExecutionListeners in the same manner.

 - AbstractTestContextBootstrapper uses the SpringFactoriesLoader to
   look up the class names of all registered default
   TestExecutionListeners and sorts the instantiated listeners using
   AnnotationAwareOrderComparator.

 - DefaultTestContextBootstrapper and WebTestContextBootstrapper now
   rely on the SpringFactoriesLoader mechanism for finding default
   TestExecutionListeners instead of hard coding fully qualified class
   names.

 - To ensure that default TestExecutionListeners are registered in the
   correct order, each can implement Ordered or declare @order.

 - AbstractTestExecutionListener and all default TestExecutionListeners
   provided by Spring now implement Ordered with appropriate values.

 - Introduced "copy constructors" in MergedContextConfiguration and
   WebMergedContextConfiguration

 - SpringFactoriesLoader now uses AnnotationAwareOrderComparator
   instead of OrderComparator.

Issue: SPR-11466

Issue: SPR-12078

Issue: SPR-12065

Replace references to the old RFC 2616 (HTTP 1.1) with references
to the new RFCs 7230 to 7235.

This commit also deprecates:
 - HttpStatus.USE_PROXY
 - HttpStatus.REQUEST_ENTITY_TOO_LARGE in favor of HttpStatus.PAYLOAD_TOO_LARGE
 - HttpStatus.REQUEST_URI_TOO_LONG in favor of HttpStatus.URI_TOO_LONG

Issue: SPR-12067