To ensure smooth transition in next stable release: people on
an older version of uBO could end up updating assets.json,
hence we needs to keep a local URL to the non-minified packaged
version of the lists.
As discussed internally with filter list maintainers.
Additionally, added a search field to filter out lists. This
is still a work in progress, no need to open issues about this,
I am aware of what is missing (i18n, more tags, etc.)
To be replaced with five sublists.
Users who are already subscribed to the list will have to manually
unsubscribe from it, which will be moved to _Custom_ section, and
subscribe to the sublists which have narrower purpose.
