Extend support for PlantUML2 export from UML2

[ansgarradermacher]

• Support of several diagrams: Class, Sequence, composite, and state
• Several enhancements, e.g. use of qualified names, visibility, static attributes, constructors/destructors

[travkin79]

Hi @ansgarradermacher,
Thank you very much for your PR. Could you please also provide a few exemplary UML files for testing purposes or (even better) a few automated tests?

In addition, please add a copyright notice to the header of each new file. There are some new file without such a notice.
BR

[ansgarradermacher]

Dear @travkin79 ,

Sorry for the late reply (I somehow missed the mail notification). I'll try to add these elements as soon as possible.

BR

[travkin79]

Hi @ansgarradermacher,
No problem, no hurry. :-)
BR

[travkin79]

Hi @ansgarradermacher,
Currently, I'm working on merging your PR. But since we moved the development to a new git repo at https://github.com/plantuml/plantuml-eclipse (see plantuml/plantuml-eclipse#2), the merge is more complicated than usually. I will not merge your PR in Hallvard's original git repo, but in the new one. You'll find the latest state in the git branch feature/fix-uml-support.

Add org.eclipse.uml2.uml to target platform (with unspecified version number, is that ok?)

I prefer using explicit versions. I took the version from the target platform definition. I don't know if it would work without the version.

Add UML2 feature. Problem? Source Header state EPL-v2, feature EPL-v1 licence

Originally, the project is licensed under EPL 1.0. I adapted the comments in the Java source code accordingly.

[travkin79]

Hi @ansgarradermacher,
Thank you for your contribution. It seems, everything works as expected in your PR. I think, I'll merge the changes in the next days and it will be part of the next release. You'll find it here soon:

New git repo: https://github.com/plantuml/plantuml-eclipse
New Eclipse update site: https://plantuml.github.io/plantuml-eclipse/