Problem: zproc_kill may kill not only this process but other child processes and parent process too
Problem: zproc_kill may kill not only this process but other child processes and parent process too

```int kill( pid_t pid, int sig )```
```If pid is equal to zero, kill() sends the signal sig to all processes whose process group ID is equal to that of the sender, except for those to which the sender does not have the appropriate authority to send a signal```

Solution: if self->pid is still not known -> do nothing

zeromq/czmq,zeromq/czmq,opedroso/czmq,opedroso/czmq,zeromq/czmq,zeromq/czmq,zeromq/czmq,zeromq/czmq,opedroso/czmq,opedroso/czmq,opedroso/czmq,opedroso/czmq,zeromq/czmq,zeromq/czmq,opedroso/czmq,opedroso/czmq,opedroso/czmq