Merge pull request #31 from agisboye/master

Fix tap handler being called more than once

Author: triniwiz

checkbox.ios.ts

@@ -196,6 +196,7 @@ export class CheckBox extends Button implements CheckBoxInterface {
 
   public onUnloaded() {
     this._iosCheckbox.delegate = null;
+    this.removeEventListener("tap");
     super.onUnloaded();
   }