Merge pull request #15 from wrapp/feature/unsubsribing

Enable a way of unbinding listeners

@@ -26,16 +26,25 @@ class Rivets.Binding
   # routines will also listen for changes on the element to propagate them back
   # to the model.
   bind: =>
-    Rivets.config.adapter.subscribe @model, @keypath, (value) => @set value
+    Rivets.config.adapter.subscribe @model, @keypath, @set
 
     if Rivets.config.preloadData
       @set Rivets.config.adapter.read @model, @keypath
 
     if @type in bidirectionals
-      @el.addEventListener 'change', (e) =>
+      @el.addEventListener 'change', @publish
+
+  publish: (e) =>
     el = e.target or e.srcElement
     Rivets.config.adapter.publish @model, @keypath, getInputValue el
 
+  # Unsubscribes from the model and the element
+  unbind: =>
+    Rivets.config.adapter.unsubscribe @model, @keypath, @set
+
+    if @type in bidirectionals
+      @el.removeEventListener 'change', @publish
+
 # A collection of bindings for a parent element.
 class Rivets.View
   # The parent DOM element and the model objects for binding are passed into the