sponsors
Merge remote branch 'origin/master' into sponsors
Merge remote branch 'origin/master' into sponsors
Made it possible to add a sponsor on a server side
Hide the 'create sponsor' tab for non-administrators
Default sponsor is now automatically set if needed

If the user is sponsored, but did not set his default sponsor yet, this is automatically done.
Also, when his default sponsor is not (no longer) one of his sponsors, the default sponsor is
changed. If the user doesn't have any sponsors at all (anymore), he also does never have a
default sponsor.
sponsors
Replaced the admin user for an admin group

Still need to change the default owner of group directories etc though!
Merge branch 'sponsors' of github.com:sara-nl/BeeHub into sponsors
Merge remote branch 'origin/sponsors' into accounting