"check_duplicate_process" feature

FEEDBACK REQUESTED
This is a little gross, but it should be safe to include as everything defaults to being turned off...  The problem I ran into was that the pid file vanished (not sure why) but the daemon was still running.. and then an IT guy came along and started it up, giving me a duplicate process, which caused a lot of mayhem. It would have been much better if the new process would have gone "hey! there's one already running.. I won't start!"

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Searches the `ps` list for anything that looks like the daemon that might
already be running.

Both the program name and arguments are checked, as it appears different
operating systems vary as to how they populate `ps`:  On ubuntu, my daemon
looks like:

    /path/to/perl /path/to/program args

but on CentOS, the very same code shows up as:

    /path/to/program args