Update to Eclipse 2018-12 & JDK-11

Purpose

The oracle JDK 1.8 (public version) is no longer maintained from the end of January. Hence, we need to switch to JDK-11 since the versions 9 and 10 are already no longer maintained. Due to the refactoring of the SDK, we now have to include OpenJFX that is missing from the SDK now. Furthermore, we need to update to version 2018-12 from Photon to obtain proper JDK-11 support.

This task includes:

- Updating the developer installation.

- Including OpenJFX (dependencies) in the oomph installation and maven.

- Fix incompatibility issues due to JDK-11.

• Update the Jenkins (maven-based) build.

(from redmine: issue id 3620, created on 2019-01-23, closed on 2019-03-12)

• Relations:
  • child #3639 (closed)
  • child #3664 (closed)