Bug Fix - #213

- Fixed bug that ignored the fact that std:cin was closed by a Ctrl-D
  in the "shell" command.  Thanks to Ian Mortimer.

src/command.cpp

@@ -1163,7 +1163,7 @@ void handleShell ()
       }
     }
   }
-  while (keepGoing);
+  while (keepGoing && !std::cin.eof ());
 }
 #endif