I must create a plug-for the reason that adds a widget in wordpress.
I'd like the widget to become in line with the current pages widget but add a chance to choose either include OR exclude by drop lower or checkbox then list pages by ID.
Following this guide I could alter the exclude to incorporate by hacking the core file situated in wordpress-includes/default_icons.php.
This is actually the original default_icons.php:
How do you result in the changes and transform it into a wordpress plugin?