files in the format: ctrl/<action>[.host][.service].
Examples:
* ctrl/recycle - recycle all services on all hosts
* ctrl/recycle.vert - recycle all services on system with hostname "vert"
* ctrl/shutdown.vert.telnet - shutdown telnet service on vert only
[service] can be "telnet", "ftp", "mail", "web" or "services".

The old recycle semaphore filenames (e.g. telnet.rec, ftpsrvr.rec, etc.) are
still supported for backward-compatibility.