resources: Update state checks

The mgmt graph depends on state tracking to eliminate redundant pokes.
With the Watch loop now able to produce events quickly, it should no
longer play a part in determining the vertex state. This simplifies the
resource API as well!

resources/exec.go

@@ -163,7 +163,6 @@ func (obj *ExecRes) Watch(processChan chan *event.Event) error {
 	}
 
 	for {
-		obj.SetState(ResStateWatching) // reset
 		select {
 		case text := <-bufioch:
 			cuid.SetConverged(false)