* pr/7530:
  Polish

Closes gh-7530

* pr/7527:
  Remove redundant toString() invocation

Closes gh-7527

* pr/7522:
  Fix broken doc formatting

Closes gh-7522

Closes gh-6496

* pr/7491:
  Polish contribution
  Detect default values defined in the parent

Closes gh-7491

Closes gh-5434

This commit adds `@JdbcTest`, a new test slice for pure jdbc tests. It
provides the same basic features than `@DataJpaTest`.

Closes gh-6563

Closes gh-7433

* pr/7510:
  Remove redundant toString() invocation

Closes gh-7510

Downgrade `maven-assembly-plugin` from 3.0 to 2.6 since the later
version contains a bug that means `recompressZippedFiles` is not
respected.

See gh-7513

* gh-7263-2:
  Add custom LayoutFactory sample
  Support custom fat jar layouts
  Rework Repacakger timeout code

Add a sample that shows how a custom LayoutFactory can be used with
both Maven and Gradle.

Closes gh-7263

Allow support for custom Lyout implementations with both the Maven
and Gradle plugin. Implementations of `LayoutFactory` can now be
specified to allow customization of the layout. In addition a
layout may now implement `CustomLoaderLayout` if it wishes to
write custom loader classes.

See gh-7263

Pull up common timeout code into Repackager and remove the need for
custom subclasses.

See gh-7263