fix for issue #293 : "rope stuck after picking crate"

fix a segfault related to tcp servers deleting themselves without removing themselves from the internal server list first. (e.g. happens if game fails to start due to missing hwengine binary. a second start attempt will lead to a segfault, even if you correctly install the binary.)

retain frontend effects setting exiting/leaving settings

Fix some warnings

Stop messages without possible desync on load from save

I didn't want to do this since it seems less clean, but... moving the stats-fix into CheckForWin, since that function is the one sending the damage stats (whyyyy?) therefore it's not sufficient to update stats after calling it, some of the stats won't be transfered to frontend then

Show who is the room admin on join (no tested, also I don't like how it is done via server warnings, but it seems there's no other solution compatible with .17)