Attempting to close a kernel results in crash

[Doug Blank]

It does stop, but exits uncleanly:

Unhandled Exception: ZeroMQ.ZmqSocketException: No such file or directory
  at ZeroMQ.ZmqSocket.HandleProxyResult (Int32 result) [0x00000] in <filename unknown>:0 
  at ZeroMQ.ZmqSocket.Bind (System.String endpoint) [0x00000] in <filename unknown>:0 
  at ZMQServer+Channel..ctor (.Session session, .Authorization auth, System.String transport, System.String address, System.String port, SocketType socket_type) [0x00000] in <filename unknown>:0 
  at ZMQServer+IOPubChannel..ctor (.Session session, .Authorization auth, System.String transport, System.String address, System.String port) [0x00000] in <filename unknown>:0 
  at ZMQServer+Session..ctor (Calico.MainWindow calico, System.String filename) [0x00000] in <filename unknown>:0 
  at ZMQServer.Start (Calico.MainWindow calico, System.String config_file) [0x00000] in <filename unknown>:0 
  at Calico.CalicoServer..ctor (System.String[] args, Calico.LanguageManager manager, Boolean Debug, Calico.Config config) [0x00000] in <filename unknown>:0 
  at Calico.MainClass.Main (System.String[] args) [0x00000] in <filename unknown>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: ZeroMQ.ZmqSocketException: No such file or directory
  at ZeroMQ.ZmqSocket.HandleProxyResult (Int32 result) [0x00000] in <filename unknown>:0 
  at ZeroMQ.ZmqSocket.Bind (System.String endpoint) [0x00000] in <filename unknown>:0 
  at ZMQServer+Channel..ctor (.Session session, .Authorization auth, System.String transport, System.String address, System.String port, SocketType socket_type) [0x00000] in <filename unknown>:0 
  at ZMQServer+IOPubChannel..ctor (.Session session, .Authorization auth, System.String transport, System.String address, System.String port) [0x00000] in <filename unknown>:0 
  at ZMQServer+Session..ctor (Calico.MainWindow calico, System.String filename) [0x00000] in <filename unknown>:0 
  at ZMQServer.Start (Calico.MainWindow calico, System.String config_file) [0x00000] in <filename unknown>:0 
  at Calico.CalicoServer..ctor (System.String[] args, Calico.LanguageManager manager, Boolean Debug, Calico.Config config) [0x00000] in <filename unknown>:0 
  at Calico.MainClass.Main (System.String[] args) [0x00000] in <filename unknown>:0 

[Doug Blank]

Fixes #151

→ <<cset 602481a4bae9>>