Convert actions to event loops

The logic gets significantly simpler due to Watchers.  But we also get
to port all the users over as well.

Change-Id: Ib4e75951e65f7431acc6c1548b7f1d20da3da295
diff --git a/y2016/vision/BUILD b/y2016/vision/BUILD
index 99c50fd..3427973 100644
--- a/y2016/vision/BUILD
+++ b/y2016/vision/BUILD
@@ -132,6 +132,7 @@
         ":vision_data",
         ":vision_queue",
         "//aos:init",
+        "//aos/events:shm-event-loop",
         "//aos/logging",
         "//aos/logging:queue_logging",
         "//aos/mutex",