Update collaborative modeling extension for Papyrus

There have been several commits in the collaborative modeling extension for Papyrus. We should merge [the changes](http://git.eclipse.org/c/papyrus/org.eclipse.papyrus-collaborativemodeling.git/) inito [our fork](https://github.com/Cooperate-Project/PapyrusCollaborativeModeling) and test the stability. Additionally, we should ensure that our solution works with the latest Papyrus version.