Error message from using uninitialized proxy

[adrianplenefisch]

It would be nice if calls to uninitialized proxies failed more clearly. Without "--with-production", calling ckLocal on an uninitialized array proxy variable gives the error "Group ID is zero-- invalid!" It would help with bug fixing if an uninitialized proxy variable knew that it was uninitialized and attempting to use it gave a more direct abort message.