Revert "Remove the unbind function from Rivets.Binding until there's a fix for unsubscribing."

This reverts commit 87f558a9.

@@ -20,6 +20,8 @@
       this.model = model;
       this.keypath = keypath;
       this.formatters = formatters != null ? formatters : [];
+      this.unbind = __bind(this.unbind, this);
+
       this.publish = __bind(this.publish, this);
 
       this.bind = __bind(this.bind, this);
@@ -64,6 +66,14 @@
       return Rivets.config.adapter.publish(this.model, this.keypath, getInputValue(el));
     };
 
+    Binding.prototype.unbind = function() {
+      var _ref;
+      Rivets.config.adapter.unsubscribe(this.model, this.keypath, this.set);
+      if (_ref = this.type, __indexOf.call(bidirectionals, _ref) >= 0) {
+        return this.el.removeEventListener('change', this.publish);
+      }
+    };
+
     return Binding;
 
   })();

@@ -49,6 +49,13 @@ class Rivets.Binding
     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