Before, we used 1.9.7.BUILD-SNAPSHOT, which according to Andy Clement
was originally an intent across a group of Spring projects he was
involved in, to ensure that SNAPSHOTS were sorted alphabetically ahead
of MILESTONEs and ahead of RCs.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Sonatype OSSRH repository rules require source and javadoc JARs in
order to create staging repositories for releases to be promoted to
Maven Central. So I added build steps to unzip the source JARs and then
create Javadocs for them.

FIXME: This configuration works with JDK 16, but throws errors on other
JDK versions, e.g. 14. It looks as if the Maven Javadoc plugin does not
do a particularly good job applying the plugin settings in a way making
it work with different JDK javadoc tool versions. I am saying that,
because when using the tool directly on the console, it works with basic
settings and the correct classpath.

In order to enable creating uber JARs via Maven Shade in the future, I
also added missing dependencies. Maven Assembly descriptors just assume
that all the necessary class files and sources already exist where it
copies them from. But several of the dependency modules were not
explicitly listed as such by the uber JAR modules. I fixed that.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

If 'name' is identical to 'artifactId' and 'packaging' has the default
value 'jar', we can just remove those tags from the POM.

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Notably, this change involves a partial revert of @4a5660b3, because we
are not using JUnit Jupiter yet but still JUnit 4 tests. See discussion
under commit at https://github.com/eclipse/org.aspectj/commit/4a5660b3.

Many other warnings - concerning both used undeclared and unused
declared dependencies - were eliminated by adding or removing the
corresponding dependencies from the POMs. Furthermore, I tried to make
sure that some clearly test-scoped dependencies are now actually
declared as such, so as to avoid unwanted transitivity bleeding into
compile scope and maybe unwanted classes ending up in uber JARs via
Maven Shade or Maven Assembly.

TODO: I am not so sure why modules other than 'run-all-unit-tests' would
depend on test JARs. I hope I broke nothing essential there. As of
today, the other modules where I found '<type>test-jar</type>'
dependencies are:
  - ajde
  - testing
  - testing-drivers
  - tests
  - weaver

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>