Rejoin shows long left users -> Cleanup on Leaving not complete

[dkgrieshammer]

Describe the bug Clicking on leave and waiting for an hour. After clicking join, the cicle other user (also left an hour ago) was still visible -> apparently user object is still in memory (left event couldnt be catched since I left before the other user.)

Expected Behavior Most of state should be cleared when leaving / joining again (except name - but this could also be saved to local storage and thus clear on every leave would be properly possible)