Add NPM shrinkwrap specification for development dependencies
Remove passenger-stress-test.1 from Debian package man pages specification
Do not half-close the session socket when communicating with Node.js.

This is because some Node.js libraries watch for the 'end' event on
the socket, and expect the event to mean that the socket has been fully
closed. SockJS terminates its long polling timeout the moment the 'end'
event has been received.

See https://github.com/phusion/passenger/issues/1198