Custom blocked services

[binarweb]

While the custom filters works great, having to disable a service requires commenting several lines of custom filters.

It would be nice to "bundle" together a bunch of DNS rules and give them a name and have them listed in "Blocked services".

This option would allow fast disable/enable of certain custom blocked services.

If we would go further, custom blocked services could also be created using block lists.

[fernvenue]

Duplicate of #1692.