Closes #998

Schema initialization now happens in @PostConstruct (effectively)
whether it is via the Hibernate EntityManagerFactory or the
Boot DataSourceInitialization (in addition or instead). The data.sql
script if it exists is still executed on an event fired from the
other places, so those tests are passing.

Flyway and liquibase have bean factory post processors (like
the one they use to order the audit aspect in Spring Data) that
enforce a dependency on those components from the EntityManagerFactory.
So Hibernate validation is still happy (and there are 2 tests to
prove it now as well).

Fixes gh-1022

ElasticSearchAutoConfiguration depends on two Spring Data Elasticsearch
classes (TransportClientFactoryBean and NodeClientFactoryBean), however
it’s only conditional on Elasticsearch itself being on the classpath.
This lead to start up failures due to a ClassNotFoundException. Its
@ConditionalOnClass configuration has been updated so that the
auto-configuration will only be enabled if both Elasticsearch and Spring
Data Elasticsearch are on the classpath.

The dependencies on TransportClientFactoryBean and NodeClientFactoryBean
were ‘hidden’ in ElasticsearchProperties. The logic that uses these
types has been moved into ElasticSearchAutoConfiguration so that the
usage of the types and the related @ConditionalOnClass configuration
is in the same file.

Fixes #1023

Despite Javassist 3.18.2-GA being available, it has not be upgraded.
This is to keep it in sync with Hibernate.

In the absence of a @GrabMetadata annotation,
DependencyResolutionContext provided no dependency management. This
was leading to incorrect dependency versions being pulled in. This
commit intializes the context with default dependency management that
will be replaced should @GrabMetadata be encountered.

Fixes #1021

Irritatingly a ResourceBundleMessageSource never gives up trying to
create a resource bundle for every message resolution, so to stop
it logging all those warnings (and probably sucking performance-wise)
we need to disable the MessageSource if a bundle is not provided.

Fixes gh-1019

Fixes gh-668 (if the asciicdoc compiles)

fixes #1018

The maven plugin now forks a process to start the application so
mvnDebug cannot be used anymore. This commit replaces the reference
of mvnDebug to a link to an example of the maven plugin.

Fixes gh-992

Fixes gh-999

Fixes gh-1011

Fixes gh-1012

(If we ever want to modularize this will make it less painful)

Fixes gh-1015

This is *really* nasty (and led me to discover a related bug
https://jira.spring.io/browse/SPR-11844), but fortunately easy to
hide from users once you have a test case.

The problem is that Spring Security registers a `BeanPostProcessor`
to handle `GlobalAuthenticationConfigurerAdapters`, and Boot
registers a `BeanPostProcessor` to handle injecting the packages
to scan into an `EntityManagerFactory` from `@EntityScan`. The
clash comes because the `EntityScanBeanPostProcessor` wants to be
postprocessed by the Security postprocessor, but if the Security
configuration depends on JPA it won't be ready in time.

The fix (or workaround) depending on how you look at it is to
prevent the other bean post processors from taking an interest in
`EntityScanBeanPostProcessor` at all (mark it as synthetic).

Fixes gh-1008

Added 2 new spring.datasource.* properties ("data" like
"schema", and "deferDdl" like the "spring.jpa.hibernate.*"
flag). The SQL scripts are then run separately and the "data"
ones are triggered by a new DataSourceInitializedEvent,
which is also published by the Hibernate DDL schema export.

Fixes gh-1006

Fix package tangle in CLI my extracting ExitStatus to a status package.

See gh-1004

Fix package tangle by moving DependencyResolutionContext from the
compiler package to grape.

See gh-1004

Reorganize the `jms` package into `hornetq` and `activemq` sub-pacakges.

Fixes gh-1005

Restore test classes accidentally deleted and ignored in c43fd04f.

See gh-408

Add unit tests for elasticsearch packages. Also refactor some
of the existing tests to prevent Repository clashes.

See gh-408

Add auto-configuration and starters for Elasticsearch.

Fixes gh-408

Update all relevant starter POMs to include a `spring-core` dependency
with an exclusion on `commons-logging`. This prevents `commons-logging`
and `jcl-over-slf4j` from both being on the classpath.

Also add enforcer rules to ensure that commons-logging doesn't sneak
back in, and that there is no dependency convergence. (some additional
libraries were required in spring-boot-dependencies)

Tested with a sample maven project as well as using the `spring jar`
command.

Fixes gh-985

Hopefully preventing any accidental commits.

Closes #1002

Provide auto-configuration support for HornetQ JMS broker, along with
an additional starter POM.

The connection factory connects to a broker available on the local
machine by default. A configuration switch allows to enable an embedded
mode that starts HornetQ as part of the application.

In such a mode, the spring.hornetq.embedded.* properties provide
additional options to configure the embedded broker. In particular,
message persistence and data directory locations can be specified. It is
also possible to define the queue(s) and topic(s) to create on startup.

Fixes: gh-765

Fixes #1003