Closes gh-2896

Closes gh-2885

See gh-2899

* patch-1:
  Add handlebars starter to community contributions

It converts everything to a String so it isn't helpful to use
it as a default.

Fixes gh-2891.

Previously ManagementSecurityAutoConfiguration used Spring Security's
default realm of "Realm" when authentication failed. This was confusing
because when prompted for authentication (i.e. no credentials provided)
the realm "Spring" was requested.

This commit ensures the Realm that is used is consistent for all of of the
security auto configuration.

Fixes #2466

See gh-2719

See gh-2883

GemFire 8.0 depends on two different versions of xml-apis:xml-apis and
org.eclipse.jdt.core.compiler:ecj. This commit adds dependency
management for those two dependencies to address the dependency
convergence errors reported by Maven’s enforcer plugin.

GemFire 8.0 also depends on commons-logging and Spring Boot starters
should use jcl-over-slf4j instead. This commit adds an exclusion for
commons-logging

GemFire 8.0 depends (optionally) on spring-data-gemfire and
spring-data-gemfire depends on GemFire, i.e. there’s a dependency cycle
between the two projects. This commit breaks this cycle by adding an
exclusion for spring-data-gemfire to the dependency management for
com.gemstone.gemfire:gemfire.

This commit should be reverted once the problems with GemFire’s
dependencies have been addressed. See gh-2884.

Closes gh-2859
See gh-2673

Closes gh-2838

Closes gh-2835

Closes gh-2832

Closes gh-2836

Closes gh-2846

Closes gh-2854

In addition to the changes already made in 1.2.x, this commit updates
the tests in spring-boot-actuator to ensure that any Elasticsearch
data files are written into the target directory. This avoids problems
when switching branches caused by different versions of Elasticsearch
trying to read the files.

By default, Elasticsearch writes it data to ./data. This led to data
being left on the filesystem after a mvn clean which could cause
failures when moving between branches that use different versions of
Elasticsearch.

This commit updates the tests for the Elasticsearch sample and
the Elasticsearch auto-configuration classes to write the
Elasticsearch data and logs into the target directory.

This reverts commit b1c0a7cd.

The plugin publishing process has moved to a new plugin-based approach
that brings with it some significant limitations:

 - There's no staging to allow the promotion of good release builds
 - There's no easy way to upload an existing artifact
 - There's no control over the published pom.

The risk brought by these limitations, particularly the first, are
too great so we will no be publishing the Boot plugin to the Portal
until they're resolved.

Changing the plugin's ID was a breaking change that would require
users to do some work when they upgrade to Boot 1.3. The ID of the
plugin was changed purely so that it met the Portal's requirements.
Given that the plugin will not be published to the Portal for the
foreseaable future there's no need for us to inflict a breaking change
on people when there will be no benefit.

See gh-1567

Remove the configuration map defined in `GroovyTemplateProperties` which
isn't used. Ironically, that configuration map was exposed with the exact
same prefix as `GroovyMarkupConfigurer`, which broke IDEs support since
two entries had the exact same prefix.

Fixes gh-2840

Add an entry for `flyway.*` to make it more explicit that any public
property of the auto-configured `Flyway` object can be set via the
`flyway` prefix.

Closes gh-2667

Update JarWriter to set the entry timestamp for nested jars. The
timestamp is set to same time as the first (non directory) entry in
the nested jar.

This change should make it easier to created layered docker images.

Fixes gh-2807

See gh-2633

Update CacheStatisticsProvider to use a generic to indicate the type
of cache supported. Also extract individual CacheStatisticsProvider
implementations and made statistics an auto-configuration.

See gh-2633

This reverts commit 54e12a07.

The changes made in spring-projects/spring-framework@e403aefe cause
SampleTomcatTwoConnectorsApplication to fail to launch. The port bean,
typed as an int, is coerced into an Integer when the bean’s created. The
port() method is then called, and the proxy’s bean method interceptor
complains as it’s expecting the port bean to be an int but it’s actually
an Integer. Changing the port() bean method’s return type to Integer
works around the problem.

SpringApplicationLifecycle provides lifecycle operations on the current
Spring Boot application. It can be registered as an MBean of the platform
MBean server if a specific property is set. Besides, the JMX name can
also be customized via a property in case more than one Spring Boot
application is started in the same process.

The Maven plugin uses that MBean to check that the application is ready
before ending the "start" phase. It uses it to trigger a proper shutdown
of the application during the "stop" phase.

If the process has to be forked, the platform MBean server is exposed on
a configurable port so that the maven plugin can connect to it.

Such change permits the maven plugin to integrate a classical integration
test scenario where the "start" goal is invoked during the
pre-integration phase and the "stop" goal during the post-integration
phase.

Closes gh-2525

To allow us to determine the type that Spring Integration’s
GatewayProxyFactoryBean will create, the bean definition created by
MessagingGatewayRegistrar needs to set the factoryBeanObjectType
attribute. The current implementation of BeanTypeRegistry requires the
attribute’s value to be a Class, however this would require Spring
Integration’s namespace handler to load the class and class loading
should be avoided in namespace handlers.

This commit updates BeanTypeRegistry so that it supports both Class and
String values for the factoryBeanObjectType. If the value is a String
it will interpret it as a class name and attempt to load it.

See gh-2811