Previously, a property holding an array did not have a proper default
value in the meta-data even though the related field was initialized
properly.

An explicit support for arrays has been added. The "defaultValue" now
holds the default value for singular properties or an array of values for
array-based properties. If the value is initalized with an empty array,
the default value is an empty array as well.

Closes gh-1996

Fixes gh-1439

Previously, any valid property was added to the meta-data of the current
group. This can be annoying for types that are not meant to be bound from
a simple string value. ClassLoader is one example.

A list of well-known types has been added: if the property type matches
an element of this list, it is ignored.

Fixes gh-2012

Fixes gh-2041

Update YamlPropertySourceLoader to use a MapPropertySource rather than
a PropertiesPropertySource to ensure that the underlying order is
retained.

Fixes gh-2022

Upgrade to the SNAPSHOT so that CI will catch any problems early.

See gh-2038

Add ConfigurationWarningsApplicationContextInitializer to report
warnings for common configuration mistakes. Currently the initializer
will log a warning if @ComponentScan is used on a @Configuration class
in the "default" package.

Fixes gh-2050

Closes gh-2049

Fixes gh-2048 and fixes gh-2051

* spring-jms-pub-sub-fix:
  Apply pubSubDomain property to ContainerFactory

Previously, tuning the pubSubDomain flag only impacted the created
JmsTemplate leaving any default listeners with the default settings.

If no default JmsListenerContainerFactory is defined, the created
one is using that property as well now.

Closes gh-2044

SecurityAutoConfiguration, via its import of
AuthenticationManagerConfiguration, requires spring-security-config
to be on the classpath as AuthenticationManagerConfiguration extends
GlobalAuthenticationConfigurerAdapter from spring-security-config.

This commit makes SecurityAutoConfiguration conditional on the
presence of GlobalAuthenticationConfigurerAdapter so that the
auto-configuration will be disabled in its absence rather than causing
an app to fail to start.

Closes gh-2046

This commit adds support to the CLI for launching a custom
SpringApplication implementation. The class that is launched can be
configured using the spring.application.class.name System property
or the SPRING_APPLICATION_CLASS_NAME environment variable with the
former taking priority.

Closes gh-2030

Closes gh-2043

See gh-1995

Conflicts:
	spring-boot/src/main/java/org/springframework/boot/logging/LoggingApplicationListener.java

Change the visibility of ErrorPageFilter to public to fix
IllegalAccessException errors on certain servlet containers.

Fixes gh-2026

Use putIfAbsent to ensure atomic creation of lock objects.

Fixes gh-1995

When the user provides their own AuthenticationManager we do a lazy
initialization and didn't (till now) inject the AuthenticationEventPublisher

Fixes gh-2033

Shares the /health endpoint request mapping between security config
and MVC dispatcher. Generalizes so that instead of a marker
interface (AnonymouslyAccessibleMvcEndpoint), an MvcEndpoint
signals that it wants to control its own access rules by adding
a Principal to the @RequestMapping method parameters (more @MVC).

Fixes gh-2015 slightly differently

The changes in 3bb598a4 overload the health endpoint's sensitive
property such that it's now considered sensitive if management
security is enabled. When an endpoint is sensitive anonymous
access is prevented. This breaks the health endpoint which should
return a filtered view of the server's health when it's accessed
anonymously rather than rejecting the request.

This commit introduces AnonymouslyAccessibleMvcEndpoint, a marker
extension of the MvcEndpoint interface. It is implemented by
HealthMvcEndpoint. ManagementSecurityAutoConfiguration has been
updated to allow anonymous access to endpoints that aren't sensitive
or that implement AnonymouslyAccessibleMvcEndpoint.

Fixes gh-2015

Previously, any property defined in a @Deprecated class were not marked
as deprecated as only the getter or field was inspected for the
annotation.

An additional check on the class has been added to handle this case.

Fixes gh-2014

Fixes gh-1999

Set the field javadoc of many properties that are managed via
configuration so that the "description" field is available in the
meta-data.

Closes gh-1808