Set exports.PhusionPassenger in node-loader.js so that apps can check whether the module parent is node-loader.js
When the Watchdog needs to forcefully terminating all agents and subprocesses, give them 1 second to respond to SIGTERM so that things like lock files can be cleaned up gracefully
The Meteor loader should advertise its own PID instead of that if its child process, so that the loader can be responsible for cleaning up the entire process group.