Fixed issue 630
27 commits. Highlights:
- Fixed issue 630 by hooking up correctly into the Team synchronization feature.
- Requirements moved to Java 11, Eclipse 2021-12.
- General update of dependencies (Tycho, Guava, etc.).
- Dropped support for Mylyn.
- Reduced uses of Guava in anticipation of the removal of Guava as a dependency.
- Many bugfixes and code rewrites.