Update MustacheViewResolver so that buildView() is called to create
the MustacheView. This sets fields such as `contentType` and allows us
to remove explicit setApplicationContext() and setServletContext()
calls.

Fixes gh-3265

Fixes gh-3276

Fixes gh-3356

GzipFilterProperties uses HttpMethod so GzipFilterAutoConfiguration,
which uses GzipFilterProperties, needs to be conditional on HttpMethod
being on the classpath.

Closes gh-3362

There is a new spring.factories entry for
org.springframework.boot.actuate.autoconfigure.EndpointWebMvcConfiguration
which loads extra beans into the MVC config for the Actuator.
If the management context is a child context all the beans go in the
child (except the Spring Security filter still). A big bonus is that
you can add WebConfigurerAdapters to configure static resources etc.
A new component called ManagementContextResolver can be used to
locate the ApplicationContext for the MVC endpoints.

Fixes gh-3345

* pr/3324:
  Fixup sample Ant build

Fixes gh-3324

* pr/3357:
  Fix typo

Fixes gh-3357

* pr/3339:
  Create Apache Ant sample
  Create spring-boot-antlib module

See gh-3339

Create a new spring-boot-antlib module which allows Apache Ant users
to easily create executable jars.

Fixes gh-3339

* pr/3341:
  Cleanup logging so execution order is unimportant

Fixes gh-3341

Update AbstractLoggingSystemTests to use a TemporaryFolder rule.

Fixes gh-3349

Rename the `html5AppCache` property from `ResourceProperties.Chain` to
`html-application-cache`.

Fixes gh-3354

By default, Jetty uses a singleton shutdown thread, registered as a
shutdown hook, to stop its components. This single thread breaks the
restart logic in devtools as a second restart causes a second attempt to
start the singleton shutdown thread which fails with an
IllegalStateException. This processing is unnecessary in a Spring Boot
application as the application context’s lifecycle when ensure that
Jetty is shutdown.

This commit updates the embedded Jetty container to remove its
components from Jetty’s shutdown thread. This leaves the thread with
no components to manage at which point it removes its registration as a
shutdown hook.

Closes gh-3343

Closes gh-3325

Closes gh-3296

See gh-3296

* pr/3346:
  Polish

Closes gh-3346

Fixes gh-2816

* pr/3344:
  Polish doc

Closes gh-3344

* pr/3123:
  Polish
  Improve Spring Resource Handling support

Polish resource handling chain support. Make sure that the chain is
enabled automatically if at least one strategy is enabled.

See gh-1604

This commit improves support of the Resource Handling features
introduced in Spring Framework 4.1. Those features add new ways to
resolve and transform static resources in applications.
See [this blog
post](https://spring.io/blog/2014/07/24/spring-framework-4-1-handling-static-web-resources)
for more details.

The `ResourceUrlEncodinFilter` is added for compatible template engines:
Velocity and Thymeleaf. It assists them with rewriting the URLs of
static resources when rendering templates.

New keys are added in the `ResourceProperties` in order to configure
the Resource Handling chain. `ResourceResolvers` and
`ResourceTransformers` are registered accordingly in
`WebMvcAutoConfiguration`.

Here is an example of enabling a `ContentVersionStrategy` on all
static resources, meaning their names will be changed for cache
busting purposes by adding a content hash at the end of the file name.
Like "/js/jquery.js -> /js/jquery-872ca6a9fdda9e2c1516a84cff5c3bc6.js".

```
spring.resources.chain.enabled:true
spring.resources.chain.strategy.content.enabled:true
spring.resources.chain.strategy.content.paths:/**
```

Closes gh-1604
Closes gh-3123

* pr/2713:
  Fix logout in sample secure web applications

Fixes gh-1536