Added saveAsImage functionality to threshold
Added saveAsImage functionality to threshold

jeremypoulter/emoncms,emoncms/emoncms,chaveiro/emoncms,jeremypoulter/emoncms,emoncms/emoncms,chaveiro/emoncms,inverse/emoncms,inverse/emoncms,emoncms/emoncms,jeremypoulter/emoncms,thaipowertech/emoncms,thaipowertech/emoncms,inverse/emoncms,emoncms/emoncms,jeremypoulter/emoncms,chaveiro/emoncms,chaveiro/emoncms,thaipowertech/emoncms,emoncms/emoncms,thaipowertech/emoncms,inverse/emoncms