resources: Simplify resource Converger and Startup code

This takes the Converged initialization and Startup patterns that are
common in all resources, and bakes it into the core engine. This way
resource writing is much more concise and there is less boilerplate!

resources/timer.go

@@ -79,22 +79,17 @@ func (obj *TimerRes) Watch(processChan chan event.Event) error {
 	}
 	obj.SetWatching(true)
 	defer obj.SetWatching(false)
-	cuid := obj.converger.Register()
-	defer cuid.Unregister()
-
-	var startup bool
-	Startup := func(block bool) <-chan time.Time {
-		if block {
-			return nil // blocks forever
-			//return make(chan time.Time) // blocks forever
-		}
-		return time.After(time.Duration(500) * time.Millisecond) // 1/2 the resolution of converged timeout
-	}
+	cuid := obj.Converger() // get the converger uid used to report status
 
 	// create a time.Ticker for the given interval
 	obj.ticker = obj.newTicker()
 	defer obj.ticker.Stop()
 
+	// notify engine that we're running
+	if err := obj.Running(processChan); err != nil {
+		return err // bubble up a NACK...
+	}
+
 	var send = false
 
 	for {
@@ -113,13 +108,9 @@ func (obj *TimerRes) Watch(processChan chan event.Event) error {
 		case <-cuid.ConvergedTimer():
 			cuid.SetConverged(true)
 			continue
-
-		case <-Startup(startup):
-			cuid.SetConverged(false)
-			send = true
 		}
+
 		if send {
-			startup = true // startup finished
 			send = false
 			if exit, err := obj.DoSend(processChan, "timer ticked"); exit || err != nil {
 				return err // we exit or bubble up a NACK...