[bug] FCGI scripts will not always restart when they are updated.
- exit(0) was caused only when script file is updated: On binary distributions this assumption is not true. If would be caused anytime when timestamp is simply changed. - The time of startup was used for origin of change. Timestamp of script would be used instead. - Non-standard `SCRIPT_FILENAME` environment variable was referred. Instead use `$PROGRAM_NAMe` (`$0`).