Update JarURLConnection & Handler so that a shared static final
connection is returned for entries that cannot be found.

See gh-6215

Closes gh-6142

Remove SessionFactoryProvider since it's no longer needed for
auto-configuration.

See gh-6142

Add a new `@EntiyScan` annotation that's used by auto-configuration to:
* Set JPA packagesToScan.
* Set Neo4J's SessionFactory packages.
* Set the initial entity set for Spring Data MongoDB, Cassandra and
  Couchbase mapping contexts.

Additionally deprecate `@org.springframework.boot.orm.jpa.EntityScan`.

See gh-6142

Remove `@NodeEntityScan` in preparation for a unified `@EntityScan`
annotation.

See gh-6142

Move Neo4J auto-configuration from `autoconfigure.neo4j` to
`autoconfigure.data.neo4j` since it's intrinsically linked to Spring
Data.

See gh-5458
See gh-6142

This commit improves the performance of JarURLConnection. There are two
main changes:

Firstly, the way in which the spec is determined has been changed so
that it’s no longer necessary to create an absolute file. Instead,
the JarFile’s pathFromRoot is used to extract the spec from the URL
relative to the JarFile.

Secondly, the number of temporary Objects that are created has been
reduced, for example by tracking an index as we process a String
rather than creating a new substring for each iteration.

See gh-6215

JarURLConnection is very performance sensitive. The change in 3772d9f9
meant that every JarURLConnection would create a FilePermission,
irrespective of whether it was actually used.

This commit updates JarURLConnection to create its FilePermission
lazily. When there is no security manager a permission will no longer
be created at all.

Closes gh-5411
See gh-6215

Update JarURLConnection.getNormalizedFileUrl so that expensive absolute
file lookups are cached.

See gh-6177
See gh-6109

springloaded isn't required in any of the samples, yet some of them
make use of it without being a springloaded-specific sample. This
is creating the false impression that springloaded is necessary in
cases where it's not.

Closes gh-5524

This commit moves the Jest auto-configuration from `spring.jest` to
`spring.elasticsearch.jest`

Closes gh-6032

Improve startup times (although not by much) by adding more background
pre-initializers and lazily evaluating the whitelabel SpEL view.

See gh-6177

* pr/6202:
  Remove unnecessary constructor

Closes gh-6202

Closes gh-6109

Existing apps get a NoSuchMethodError before this change because
they were compiled expecting a different signature for the
deprecated FilterRegistrationBean constructor.

The upgrade to Hibernate 5.2.0.Final has provide to be too
problematic to live with. It requires Java 8, is incompatible with
a number of other projects in the Hibernate ecosystem, and it's
unclear for how long it will be maintained. We'd previously used
Hibernate 5.1.0.Final but its maintenance is also unclear with
Hibernate 5.1.1.Final being more than 3 months overdue.

This commit drops back to Hibernate 5.0.9.Final. This has a few
advantages:

- It's Java 7 compatible
- It's had some time to mature and should be reasonably free of
  regressions for those moving from 4.3.x
- It's used in both Wildfly and JBoss EAP so there's a fair chance
  that it will continue to be maintained.

Closes gh-6198

See gh-6197

When a custom management.port is used, the child context is configured
with an EmbeddedServletContainerFactory bean that has the same class
as the parent context’s EmbeddedServletContainerFactory bean. This
ensures that the child context uses the same type of embedded container
as its parent when there are multiple embedded containers on the
classpath. It also causes a failure when the custom
EmbeddedServletContainerFactory subclass cannot be instantiated, for
example because it’s an anonymous inner-class.

This commit improves the diagnostics so that we fail fast with an
information exception message when we detect that the embedded servlet
container factory bean’s class cannot be instantiated.

Closes gh-6193

Previously, JarURLConnection assumed that that URL with which it was
created would contain the absolute path of the underlying jar file.
This meant that when it was created with a relative URL, it could fail
to find an entry or throw a StringIndexOutOfBoundsException.

This commit updates the logic for normalizing the input URL so that
both absolute and relative URLs are supported.

Closes gh-6109

* pr/6191:
  Update libraries supported by jsf-spring-boot-starter

Closes gh-6191

See gh-5330

See gh-2893