When running an application, --local can be used to collect the
application's dependencies in a local directory. Prior to
AetherGrapeEngine being introduced, using --local would result in the
dependencies being written to ./grapes. When AetherGrapeEngine was
introduced --local no longer had any effect.

This commit updates AetherGrapeEngine so that it honours --local,
writing its dependencies to ./repository. When --local is not specified
dependencies are written to ~/.m2/repository (the standard location
for the local Maven cache). As part of this change TestCommand has
been refactored so that it lazily initialises its GroovyCompiler. This
ensures that RunCommand has a chance to set the system property that
backs --local before AetherGrapeEngine is initialised and accesses the
property.

Fixes #99

Generate springcli.properties in generate-resources so that it can
be copied by the resources plugin in the process-resources phase.

Failing test cases weren't not properly handled and instead caused
test to break. Added a test case and verified it works for both JUnit
and Spock.

Previously: properties(Map) behaved differently to
properties(String...).

Fixed by merging the implementations.

Also added properties(Properties).

Previously the management endpoint filter was applied to all requests
if the user had disabled security.management.enabled, but since it
had no security applied it was letting all requests through.

The fix was to explicitly exclude the whole enclosing configuration
and carefully ignore the management endpoints in the normal security
chain.

Fixes gh-100.

3d714d30 allowed all integration tests to download snapshots and
milestones. The test for the integration sample, which depends upon a
milestone, no longer needs to be a special case.

Extract and refactor inner-classes from the GroovyCompiler to improve
code readability.

RelaxedDataBinder now supports "env var" style variables that include the
path prefix, e.g. FOO_BAR_BAZ=boom will bind to a bean with property "baz"
and a binder with prefix "foo.bar".

Fixes gh-98

Extract logic from SampleIntegrationTests into a reusable JUnit @Rule.

Aplly consistent formatting, drop JDK 8 support and cleanup repo
locations to use spring.io.

Update CLI SampleIntegrationTests to no longer disable snapshot repos.

- Found typo while reading.

Previously, Repackage would attempt to repackage every jar in the
project. This would cause it to incorrectly attempt to repackage source
and javadoc jars.

This commit updates Repackage so that it ignores any jar with a
classifier. Hopefully this is a reasonable approximation for ignoring
'special' jars that should not be repackaged such as sources and
javadoc.

Previously, GrapeEngineInstaller would only install its GrapeEngine
if an engine had not already been installed. As the Grape class stores
the engine in a static field, this meant that the engine would only be
installed once for the lifetime of Grape's classloader. This caused
an ordering issue in SampleIntegrationTests.

The test for the integration sample clears the
disableSpringSnapshotRepos system property to allow M1 of the
integration DSL to be resolved. However, this property is only
examined and honoured in AetherGrapeEngine's constructor. If another
test had run and had already created and installed an
AetherGrapeEngine, the new AetherGrapeEngine that allowed the use of
snapshot repositories would not be installed and the test would fail.

This commit updates GrapeEngineInstaller so that it always installs
its GrapeEngine, overwriting any previously installed engine.

Previously, the Ivy-based Grape engine used a system property,
disableSpringSnapshotRepos, to control whether or not Spring's
snapshot and milestone repositories were used for dependency
resolution. This commit adds the same capability to AetherGrapeEngine.

[#59489826]