#1421

- no more duplicates of annotation by addClassAnnotation.
- Look for annotation in all parts of the class. If found just update it.
- If no annotation is found then add a new one in public section.

git-svn-id: https://openmodelica.org/svn/OpenModelica/trunk@12377 f25d12d1-65f4-0310-ae8a-bbce733d8d8e