[884] Fix eclipse project setup: Add JUnit 5, ByteBuddy

[JanecekPetr]

As discussed in #884:

• switched JUnit 4 for JUnit 5
• added ByteBuddy for the benchmarks project
• and, most controversially, switched to JDK 11 as there are classes using Java 9+ features. I can roll this back, but it makes a fair amount of classes uncompilable.

[theigl]

@JanecekPetr:

switched JUnit 4 for JUnit 5

JUnit 5 provides a single (unfortunately named) artifact as well:

An executable junit-platform-console-{platform-version}-standalone.jar artifact containing the Jupiter and Vintage test engines with all dependencies is generated by the default build process, stored in junit-platform-console/build/libs and published to the Maven Central repository. It provides hassle-free usage of JUnit 5 in projects that manually manage their dependencies similar to the plain-old JAR known from JUnit 4.

Could you try if this artifact works for the build? A single JAR would be much easier to manage.

and, most controversially, switched to JDK 11 as there are classes using Java 9+ features. I can roll this back, but it makes a fair amount of classes uncompilable.

We should be safe, since our CI builds still run the tests on JDK 8.

[JanecekPetr]

Fair enough, fixed!

[theigl]

We should be safe, since our CI builds still run the tests on JDK 8.

Sorry I wasn't really clear here: I meant, that you can change the JDK to 11 if you want, because our CI build will catch any incompatibilities with JDK 8 in the main source folder.

LGTM!