Make sure that we unsubscribe the whole keypath observer when unbinding a binding for good. [#223]

@@ -107,7 +107,10 @@ class Rivets.Binding
 
   # Unsubscribes from the model and the element.
   unbind: (silent = false) =>
-    @binder.unbind?.call @, @el unless silent
+    unless silent
+      @binder.unbind?.call @, @el
+      @observer.unobserve()
+
     @view.adapters[@key.interface].unsubscribe(@model, @key.path, @sync) if @key
 
     if @dependencies.length

@@ -39,3 +39,8 @@ class KeypathObserver
       current = @view.adapters[token.interface].read current, token.path
 
     current
+
+  unobserve: =>
+    for token, index in @tokens
+      if obj = @objectPath[index]
+        @view.adapters[token.interface].unsubscribe obj, token.path, @update