Update BeanTypeRegistry to gracefully ignore LoadBeanClassException and
BeanDefinitionStoreException exceptions in the same way as
DefaultListableBeanFactory.doGetBeanNamesForType() does.

Fixes gh-1955

Fixes gh-1756

Spring initializr now declares an improved metadata format (v2).

InitializrServiceMetadata has been updated to parse this format. Note
that the client could be further improved by using HAL generated links.

Closes gh-1953

Uses raw class instead of Java Type API (which has a
default method in 1.8, unavailble in 1.7).

Users can add @Beans of this type to customize the
EndpointHandlerMapping (e.g. add interceptors) even if
it is in a child context.

Fixes gh-1933

Eclipse (by default) does not create the JSON metadata when
it compiles the @ConfigurationProperties beans. So running on
the command lilne gets scarily different than in an IDE. Fixed
by externalizing the metadata location and setting it to something
empty in the tests.

Closes gh-1269

Including maps and lists. Beans with no metadata (in
/META-INF/*spring-configuration-metadata.json) are just serialized
as they come (so might have problems like cycles). Serialization
errors are caught and rendered as an "error" for that bean. Any
problems can be fixed by preparing metadata and specifying which
properties are to be rendered that way.

Fixes gh-1746, fixes gh-1921

Add LICENSE.txt file and make it clear in the README file that we
are Apache 2.0

Fixes gh-1952

Switch implementations of ApplicationListener<ContextRefreshEvent> for
SmartInitializingSingleton when possible.

Fixes gh-1939

Closes gh-1779

See gh-1779

Accidentally committed in 4668f597

See gh-1950

* ssl-keystore-classpath-test:
  Add Jetty SSL keystore in classpath test

Update JettyEmbeddedServletContainerFactoryTests to test loading an
SSL keystore from the classpath. Currently this is a Jetty only feature,
although if https://issues.apache.org/bugzilla/show_bug.cgi?id=56777 is
fixed we could do the same thing with Tomcat.

Closes gh-1943

Fixes gh-1948

Update RelaxedConversionService to support more relaxed enum binding.

Fixes gh-1950

Previously, HypermediaAutoConfiguration would trigger the creation of
an ObjectMapper bean named _halObjectMapper. This bean did not have the
spring.jackson.* configuration applied to it, however its presence
would revent JacksonAutoConfiguration from creating its
ObjectMapper. This left the user with an ObjectMapper that did not
honour the spring.jackson.* configuration.

This commit updates HypermediaAutoConfiguration to use the
Jackson2ObjectMapperBuilder that may have been created by
JacksonAutoConfiguration. If the builder exists it is used to configure
the _halObjectMapper bean.

Fixes gh-1949

The http.mappers.* configuration properties assumed that the mapping
was JSON (on of the property names was jsonPrettyPrint) and also only
exposed a small subset of the configuration options supported by
Jackson (and GSON). The property names implied that it would configure
all HTTP mapping, however it was ignored by GsonAutoConfiguration.

This commit deprecates the support for http.mappers.* in favour of
configuring Jackson or Gson instead. Jackson can be configured
declaratively using the spring.jackson.* properties or programtically.
Gson can be configured programatically by using a GsonBuilder to
create a Gson instance with the desired configuration.
gh-1946 has been opened to add support for declarative configuration
of Gson.

Closes gh-1945

Closes gh-1919

Previously, only the http.mappers.json-sort-keys property was applied
by JacksonAutoConfiguration. This commit updates it to also apply the
http.mappers.json-pretty-print property as well.

See #1919

Closes gh-1923

See gh-1923

Conflicts:
	spring-boot-dependencies/pom.xml

Closes gh-1936