* gh-5289:
  Polish contribution
  Update JarURLConnection to support jar:file://… URLs

Previously, JarURLConnection would fail when created with a URL that
began with jar:file:// as the double-slash is not included in jarFile.getUrl().getFile().

This commit updates JarURLConnection to normalise the value return from
url.getFile() to remove a double-slash when present.

Fixes gh-5287
Closes gh-5289

* gh-4361:
  Add dependency management for org.hibernate:hibernate-java8

Closes gh-4361

* gh-5397:
  Improve repeatability of launch script tests

Previously, tags were used for CentOS and Ubuntu images that may
change over time. This commit updates the Dockerfiles to use fixed
base images. For Ubuntu, a fixed tag is available. For CentOS we
have to resort to using the digest.

Closes gh-5397

* gh-5394:
  Update launch.script so popd does not print directory name to stdout

Closes gh-5394

* gh-5615:
  Remove a duplicate test

Closes gh-5615

Closes gh-5195

Closes gh-5616

* pr/5614:
  Polish

Closes gh-5614

* gh-4913:
  Allow per-http-method MetricsFilter submissions

Add `endpoints.metrics.filter.gauge-submissions` and
`endpoints.metrics.filter.counter-submissions` properties which can be
used to fine-tune how MetricsFilter submits metrics.

Use `per-http-method` to group by the the HTTP method, `merged` to
combine or both (`merged,per-http-method`) to submit both in forms.

Closes gh-5102

* gh-1826:
  Add Liquibase rollback file support

Add a `liquibase.rollback-file` property which can be used to write
a rollback file when migrations occur.

Fixes gh-1826
Closes gh-5535

Add a sample showing how Hibernate 4 can be used if necessary.

See gh-2763

Upgrade to Hibernate 5.1, whilst still retaining compatibility with
Hibernate 4.3. This commit introduces the following changes:

* Add SpringPhysicalNamingStrategy to provides lowercase/underscore
  table names support. This should be equivalent to the previous
  SpringNamingStrategy that was used with Hibernate 4. No
  ImplicitNamingStrategy is provided since the Hibernate 5 defaults
  appear to be roughly equivalent to the conventions used in Spring
  Boot 1.3
  spring.jpa.hibernate.naming.

* Migrate  `spring.jpa.hibernate.naming-strategy` to
  `spring.jpa.hibernate.naming.strategy` and provide additional
  properties for physical and implicit.

* Add `spring.jpa.hibernate.use-new-id-generator-mappings` property and
  default to `false` when on Hibernate 5 to retain back compatibility.

See gh-2763

Previously, we only had dependency management for
selenium-htmlunit-driver. It depends on three other Selenium modules
for which dependency management was not provided. This means that there
was a risk that a mixture of versions would end up on the classpath.

This commit adds dependency management for the Selenium modules upon
which selenium-htmlunit-driver depends.

Closes gh-5520

Closes gh-5444

While the benign exception that Gemfire outputs is unfortunate, it
isn't sufficient justification for adding dependency management for
Spring Shell.

Closes gh-5444

Previously, JarLauncher considered any entry whose name began with
BOOT-INF/classes/ as being a nested entry. This was incorrect as it
meant that subdirectories of BOOT-INF/classes/ would be added to the
classpath rather than just BOOT-INF/classes/ itself.

This commit updates JarLauncher so that only directory entries with a
name equal to BOOT-INF/classes are used.

Closes gh-5610

Previously, if a JarFile was created from a directory nested inside
another jar file, it would look for the manifest in
pathFromRoot/META-INF/MANIFEST.MF. This is incorrect as, unlike a
JarFile created from a jar file, the archives are one and the same
so the manifests should be too.

This commit updates JarFile so that its aware of how it was created
(direct from a file, from a nested directory, from a nested jar). If
it was created from a file or from a nested jar, it uses its manifest.
If it was created from a nested directory, it uses the manifest of the
root archive.

Closes gh-5609

Closes gh-5608

Closes gh-5607

Closes gh-5606

Closes gh-5605

Closes gh-5604

Closes gh-5603

Closes gh-5602

Closes gh-5601

Closes gh-5600