PURPOSE: execute a specific action at shut down of indigo in order to be able to finish things, ...

exeute indigo action during indigo shutdown .. triggered by shutting down this plugin

• it will test if the indig logfile indicates a complete indigo shut down
• look for "Quitting Indigo Server - stopping plugins"
  then if found, tries to find "Loading plugin" after the shutdown lines.
  if loading plugin is found , it's not a shutdown
  if not it will execute the selected action group (setup in config)