Add a built-in extension
Change how filters are loaded
Converts and filters Filters into the Extension format

As the filters are easier to edit, a huge amount of them are now gone from the
original package. They will, maybe, be back in another built-in extension.

Also, enhance the protect filter.
Update CHANGELOG
Make lowercase the core extension's name
Add a way to freeze extensions when parsing, and get a specific extension
Remove a useless built-in filter
Update Documentation