#193 Object diagram: grey out behavior

[Andreas Kaestner]

• also change font color when greying out
• different color for selected object and greyed out / selcted object and not greyed out
• behavior for adjacent links (grey out link when adjacent object is greyed out)
• behavior for association classes (grey out object => grey out connected assoc class, grey out assoc class => grey out link)

[Andreas Kaestner]

should be mostly done, i will close this ticket after i test it a bit more