PublishPress Checklists Pro 2.15.0

* Fixed: Remove unexistent dependencies for met-box.js, #231;
* Changed: Updated the base plugin to v2.4.2;

* Fixed: Fix JS error Uncaught TypeError: Cannot read property 'doAction' of undefined, #224;
* Fixed: Fix broken menu item if the user doesn't have permissions to see the menu, #226;
* Changed: Updated base plugin to v2.4.1;

* Added: Added a new task for validating links in the content, #200;
* Added: Added a new task for checking the number of external links, #201;
* Added: Added form validation for required fields in the checklists page, #175;
* Added: Added a new task for requiring approval for specific roles, #104;
* Added: Added new field for custom tasks to select which role can check/uncheck the box, #104;
* Removed: The option "Recommended: show only in the sidebar" were removed and current settings fallback to "Recommended: show in the sidebar and before publishing", which was renamed to just: "Recommended", #195.
* Changed: Changed the order of tasks in the settings page, #223;
* Changed: Updated base plugin to v2.4.0;