message: remove unnecessary using namespace, minor updates
diff: namespace ospcommon
  {
  - using namespace ospcommon;
  -
  /*! type for a socket */
  - typedef struct opaque_socket_t* socket_t;
  + using socket_t = struct opaque_socket_t*;
  /*! exception thrown when other side disconnects */
  struct Disconnect : public std::exception
  @@ -86,4 +84,4 @@ namespace ospcommon
  /*! writes a string to the socket */
  void write(socket_t socket, const std::string& str);
  -}// ::ospray
  +}// ::ospcommon
  