Add New Default Avatar [Emrikol's Fork]

I’d been manually adding custom default avatars in functions.php for a while, and it was always a hassle to edit it to change them. I decided to see if there was a plugin available to do the job, and stumbled upon “Add New Default Avatar” here: https://wordpress.org/extend/plugins/add-new-default-avatar/
It was nice, but it was missing some features such as the ability to manage avatars, upload images, and automatically resize thumbnails. So I made a few modifications ??

Features:

• Saves current default avatar before activating and restores it when deactivated
• Upload images using AJAX directly from the plugin page
• Ability to remove unneeded custom default avatars from the default avatar list