Multi Threaded Daemon - enhanced

I couldn't find a better listing category than "Server Management"... This class implements a daemon that can spawn multiple parallel threads, written entirely in PHP. It includes a sample app to monitor a "queue" directory on the filesystem and spawns up to "N" child processes to parse individual files from it. It is an enhanced version of the original Multithreaded Daemon class written by Killerwhile (phpclasses.org) - Benoit Perroud . This version provides several robustness improvements, adds support for handling signals (SIGTERM, SIGHUP) and a unique PID file to avoid starting multiple instances.