Updated vanilla example to just send a 200 and not acquire any upload streams.  Discovered problem with response never being sent, even when res.send, res.end, res.on('close'), etc. were used.  Turns out that, on error, in order for multiparty to emit 'close', we have to pipe the rest of the bytes of the file to a leaky stream.  This is done now, and works, but I should write a proper mocha test for it to prevent future regression.