[REQUEST] Equivalent of custom.css for config.js, IncludeJS and IncludeCSS

[AutoItScript]

I'm having to reedit a lot of files each upgrade. Custom.css is a great way to prevent this for general css styling but there are other edits that are commonly required. It would be very helpful if there were similar mechanisms for these areas:

• IncludeCSS - you need to edit this template in order to add custom Google fonts in a browser independent way - you can't just add the fonts to custom.css as they won't look correct on all browsers
• IncludeJS - I have to add my own links to js here for custom JavaScript, for example if I add a ckeditor plugin it may require a JavaScript lib like highlight.js
• config.js - a lot of ckeditor plugins need customisation in config.js which is nuked each upgrade. Also some built in plugins like pbckcode have been hard coded in core-JavaScript/ui.editor and can't be overridden in config.js