Update JackonAutoConfiguration to apply all http.mappers properties

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
Test that http.mappers props are applied by JacksonAutoConfiguration

Closes gh-1919
Merge branch 'gh-1919' into 1.1.x
Merge branch '1.1.x'
Deprecate http.mappers.* properties

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
Apply spring.jackson.* config to HypermediaAutoConfiguration’s ObjectMapper

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
Improve relaxed enum binding

Update RelaxedConversionService to support more relaxed enum binding.

Fixes gh-1950
Add profile to ConfigFileApplicationListener log

Fixes gh-1948
Merge branch '1.1.x'
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
Merge pull request #1943 from isopov/ssl-keystore-classpath-test

* ssl-keystore-classpath-test:
  Add Jetty SSL keystore in classpath test
Remove accidental SampleControllerAdvice test

Accidentally committed in 4668f597231ca4e6a1bf5852f3f835636cb69290

See gh-1950
Add support for using Undertow as an embedded container

See gh-1779
Polish Undertow contribution

Closes gh-1779
Merge branch 'undertow'
Add missing copyright headers
Merge branch '1.1.x'
Use SmartInitializingSingleton when possible

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

Fixes gh-1939
Fixup line endings
Polish