* pr/5773:
  Polish
  Removed redundant override of the configure method

Since the `SampleJerseyApplication` class is already passed in the
`SpringApplicationBuilder` constructor, there is no need to override the
configure method of the `SpringBootServletInitializer` class.

Closes gh-5773

Before this change the app context closes and metrics that have not
yet been exported ccan be orphaned. The design of this feature is simple:
use Closeable where possible, so that it will be called automatically
by Spring on shutdown.

Fixes gh-5771

The MetricCopyExporter has had the capability for a while to keep
track of counters internally. This change aligns that with the
PrefixMetricGroupExporter.

Fixes gh-5762

Closes gh-5748

Closes gh-5519

* pr/5745:
  Polish

See gh-4953
Closes gh-5745

Previously, the Gradle plugin would include all of the dependencies
from both the compile and runtime configurations in the repackaged
jar. In the unlikely event that the compile and runtime configurations
contained different versions of the same dependency, this would lead
to both versions of the dependency being packaged in the jar file.

The runtime configuration extends the compile configuration so, in
normal circumstances, it will contain a superset of the compile
configuration's dependencies. In the situation described above where
the two configurations contain different versions of the same
dependency the runtime configuration will only contain whichever
version of the two dependencies has "won". By default, this will
be the dependency with the higher version.

This commit updates the Gradle plugin to only include the runtime
configuration's resolved dependencies during repackaging. As explained
above, the runtime configuration extends the compile configuration so
any compile dependencies will still be included, with the added
benefit that duplicate versions of the same dependency will have been
resolved to a single, preferred version.

Closes gh-5749

Closes gh-5741

Closes gh-5757

Closes gh-5446

Closes gh-5351

Closes gh-5738

Previously, the web application context was only set on the
ServletContext in a full-blown integration test or when MockMvc was
used.

This commit updates SpringApplicationContextLoader so that the context
is also set on the context in a plain web application test (one where
MockMvc is not being used). The change is a partial backport of commit
7dffb702.

Closes gh-4370

Closes gh-2953

* pr/5720:
  Remove the second parameter of substring() if possible

Closes gh-5720

Previously, the classpath would be logged in response to the
ApplicationStartedEvent. At this point, logging could be disabled
while the logging system is being initialized, or because the
log levels configured in the environment have not yet been applied.

This commit moves the logging to happen in response to an
ApplicationEnvironmentPreparedEvent by which point the logging
system has been initialized and its levels have been configured.

Closes gh-5313

Previously, SpringBootContextLoader configured the environment with the
test property sources using an ApplicationContextInitializer. This was
because TestPropertySourceUtils did not provide a method to directly
configure the environment using properties files, it had to be done
via an application context. An unwanted side-effect of this was that
the test property sources were not being configured before
ConfigFileApplicationListener examined the environment to determine the
name and locations of the files that it should be loading.

This commit takes advantage of a new method that was added to
TestPropertySourceUtils which allows properties files to be added
directly to the environment without using an application context. This
means that the use of the ApplicationContextInitializer can be removed
and the test property sources can be applied to the environment before
the application context is created.

Closes gh-5728

Closes gh-5725

Closes gh-5722

Previously, there were two problems with DevTools’ DataSource
auto-configuration:

1. It did not tolerate a context with multiple DataSources
2. It would attempt to shut down a DataSource that had not been created
   by DataSourceAutoConfiguration and, therefore, where we could not be
   sure of its configuration.

This commit updates DevToolsDataSourceAutoConfiguration so that it backs
off unless the context contains DataSourceProperties and a single
DataSource created by DataSourceAutoConfiguration. This ensures that it
can safely use DataSourceProperties to get the DataSource’s
driver class name and accurately determine if it’s an in-memory or
external database. Shutdown is only called for an in-memory database.

Closes gh-5540

* pr/5731:
  Remove duplicate words

Closes gh-5731

* pr/5727:
  Replacing StringBuffer with lock-free StringBuilder

Closes gh-5727

Closes gh-5664

Previously, spring.thymeleaf.cache was only applied to auto-configured
TemplateResolver. This commit also applies the propery to the
auto-configured ThymeleafViewResolver.

Closes gh-5395