Implement a separate callback space so that setting callback.wrapped in adapter.…

…subscribe won't overwrite the existing wrapped function, making the binding unbindable.

@@ -64,14 +64,16 @@ class Rivets.Binding
         @set Rivets.config.adapter.read @model, @keypath
 
     if @options.dependencies?.length
-      @reset = (value) =>
+      @dependencyCallbacks = {}
+
+      for keypath in @options.dependencies
+        callback = @dependencyCallbacks[keypath] = (value) =>
           @set if @options.bypass
             @model[@keypath]
           else
             Rivets.config.adapter.read @model, @keypath
         
-      for keypath in @options.dependencies
-        Rivets.config.adapter.subscribe @model, keypath, @reset
+        Rivets.config.adapter.subscribe @model, keypath, callback
 
     if @type in @bidirectionals
       bindEvent @el, 'change', @publish
@@ -87,7 +89,8 @@ class Rivets.Binding
 
     if @options.dependencies?.length
       for keypath in @options.dependencies
-        Rivets.config.adapter.unsubscribe @model, keypath, @reset
+        callback = @dependencyCallbacks[keypath]
+        Rivets.config.adapter.unsubscribe @model, keypath, callback
 
     if @type in @bidirectionals
       @el.removeEventListener 'change', @publish