refactor redraw into pubsub and autoredraw

- pubsub is a basic pubsub impl
- autoredraw is glue code to register callback to pubsub and onevent

moved e.redraw to autoredraw

api/tests/test-pubsub.js

@@ -0,0 +1,53 @@
+"use strict"
+
+var o = require("../../ospec/ospec")
+var apiPubSub = require("../../api/pubsub")
+
+o.spec("pubsub", function() {
+    var pubsub
+	o.beforeEach(function() {
+		pubsub = apiPubSub()
+	})
+    
+    o("it shouldn't error if there are no renderers", function() {
+        pubsub.publish()
+    })
+    
+    o("it should run a single renderer entry", function() {
+        var spy = o.spy()
+        
+        pubsub.subscribe(spy)
+        
+        pubsub.publish()
+        
+        o(spy.callCount).equals(1)
+        
+        pubsub.publish()
+        pubsub.publish()
+        pubsub.publish()
+        
+        o(spy.callCount).equals(4)
+    })
+    
+    o("it should run all renderer entries", function() {
+        var spy1 = o.spy()
+        var spy2 = o.spy()
+        var spy3 = o.spy()
+        
+        pubsub.subscribe(spy1)
+        pubsub.subscribe(spy2)
+        pubsub.subscribe(spy3)
+        
+        pubsub.publish()
+        
+        o(spy1.callCount).equals(1)
+        o(spy2.callCount).equals(1)
+        o(spy3.callCount).equals(1)
+        
+        pubsub.publish()
+        
+        o(spy1.callCount).equals(2)
+        o(spy2.callCount).equals(2)
+        o(spy3.callCount).equals(2)
+    })
+})