http_server: `prefinish` vs `finish`
http_server: `prefinish` vs `finish`

Do not detach the socket from the response until all data is actually
sent to the other side.

See: https://github.com/iojs/io.js/pull/1373
PR-URL: https://github.com/nodejs/io.js/pull/1411
Reviewed-By: Chris Dickinson <38a75c4c4f5646d63b752460df745c5b937b7e58@gmail.com>
Reviewed-By: Jeremiah Senkpiel <f1782d15e31ad502ea2c097c21cc235811d0cb7c@rocketmail.com>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node