use deleteLater to ensure that AvatarVoxelSystem delete is on correct thread
reset environment on domain-server change
remove the planets from the VS environment
don't attempt to go to user without domain AND position
Merge pull request #1044 from birarda/data-server

don't goToUser without domain and position
Merge pull request #1043 from birarda/master

fix domain jumping with goToUser, remove planet environments