Closes gh-2718

Previously, the ErrorPageFilter was not invoked for async dispatches.
This meant that an error that was set during an async dispatch would
go undetected and a 200 response with an empty body would be returned.

This commit updates ErrorPageFilter to configure its
OncePerRequestFilter so that async dispatches are filtered and the
correct error handling is performed.

Closes gh-2711

Remove unwanted System.out.println call

Closes gh-2702

Update SpringApplicationContextLoader so that the MockServletContext
uses FileSystemResourceLoader. This allows `/src/main/webapp` folder
to be found.

See gh-2654

Previously, SpringBootWebSecurityConfiguration required a web
application and @EnableWebSecurity to be on the classpath.
@EnableWebSecurity is in spring-security-config so this could lead
to the configuration being active when spring-security-web isn't
on the classpath but the rest of Spring Security is.

This commit updates SpringBootWebSecurityConfiguration to also make it
conditional on a class in spring-security-web.

Fixes gh-2717

Add an additional constructor to ServletRegistrationBean that indicates
if a URL mapping is always required. If set to false, the registration
will not longer use the default '/*' mapping.

Fixes gh-2596

Fixes gh-2598

Update SystemPublicMetrics to silently ignore ManagementFactory
NoClassDefFoundErrors which can occur when deploying to Google App
Engine.

Fixes gh-2701

* vcap-service-numbers:
  Support VcapApplicationListener Number Credentials

Update VcapApplicationListener to support Number based credentials.
Previously, any service credential value that wasn't a String would
be discarded. This was particularly a problem for services that exposed
a port as a JSON Number.  This change takes numbers in the credential
payload into account, converting them to Strings so that they will pass
through the properties system properly. There's no real downside to this
as Spring will coerce them back into Numbers if needed by an application.

Fixes gh-2707

See gh-2702

* gh-2698:
  fix typo in javadoc

{@code tomat-embedded.jar} --> {@code tomcat-embedded.jar}

Add note about escaping Spring property placeholders when using Gradle
automatic expansion.

Closes gh-2695

See gh-2630

Previously, the response from /health was not cached if the request
was secure, i.e. the user has authenticated, or the endpoint was
configured as not being sensitive. 

The commit updates HealthMvcEndpoint to apply the caching logic
all the time. Users that do not want caching can disable it by 
configuring the TTL with a value of zero.

Closes gh-2630

Previously, only a handful of properties could be set when
auto-configuring an Elasticsearch client. This commit introduces support
for configuring arbitrary properties using the
spring.data.elasticsearch.properties prefix. For example,
client.transport.sniff can be configured using
spring.data.elasticsearch.properties.client.transport.sniff.

Closes gh-1838

Using a Class reference can cause reflection problems at runtime (see
gh-1065).

Closes gh-2674

Previously, a TransportClient sniff property could not be configured
while using Spring Boot’s Elasticsearch auto-configuration. This commit
adds a new property, spring.data.elasticsearch.client-transport-sniff,
that can be used to configure the TransportClient while continuing to
use the auto-configuration support.

Closes gh-1838

Wrap at 90 chars more consistently

Closes gh-2570

Conflicts:
	spring-boot-dependencies/pom.xml

Closes gh-2582

The actual required Spring Framework version is 4.1.5.

See gh-2575

The example `@Value("server.local.port")` should read
`@Value("${local.server.port}")`.

Fixes gh-2628

In ActiveMQ 5.11 the signature of
PooledConnectionFactory.setConnectionFactory has changed. It now takes
an Object rather than a ConnectionFactory. This change is not binary
backwards compatible so it causes a NoSuchMethodError as we compile
against 5.10.

This commit updates ActiveMQConnectionFactoryConfiguration to call
the setConnectionFactory method reflectively, looking for both the
ConnectionFactory and Object variants.

Closes gh-2640

Closes gh-2647

PropertySourcePropertyValues tries to process a PropertySource first
as an EnumerablePropertySource and then as a CompositePropertySource.
In Spring 4.1.2 CompositePropertySource was updated to extend
EnumerablePropertySource. This change meant that a
CompositePropertySource would always be processed as an
EnumerablePropertySource.

This commit updates PropertySourcePropertyValues to process a
PropertySource as a CompositePropertySource first and to then try it
is an EnumerablePropertySource.

Fixes gh-2608

Unfortunately it still has to happen in a @PostConstruct (otherwise
JPA never sees the schema in time), but we can delay a bit by not
using @Autowired. Appears to fix the Spring Cloud problem
(https://github.com/spring-cloud/spring-cloud-config/issues/105).

Fixes gh-2658

Spring Boot's metrics infrastructure requires a Metric to have a
Number value. Coda Hale's ThreadStatesGaugeSet includes a Gauge
named deadlocks with a Set<String> value (each entry in the set is a
description, including stacktrace, of a deadlocked thread). There's
no obvious way to coerce this to a Number, and there's already a
deadlocks.count metric in the set.

This commit updates MetricRegistryMetricReader to ignore the addition
of any Gauge with a non-Number value.

Fixes gh-2593