http://bugs.python.org/issue6382

added the shutdown_request() which can perform shutdown before calling close.  This is needed for the ForkingMixIn because different close semantics are required for child and parent process.  shutdown_request(), for TCP servers, calls socket.shutdown() and then calls close_request().  Therefore, this is not an backwards incompatible change, since subclasses that continue to override close_request() continue to work.