Each entry in such a list can now also include a subcategory
'<category>:<subcategory>'
and it is possible to use '*' or an empty string as placeholder
'*:<subcategory>', ':<subcategory>', '<category>:*'
For example
"blacklist": "imgur,*:tag,gfycat:user" or
"blacklist": ["imgur", "*:tag", "gfycat:user"]
will filter all 'imgur' extractors, all extractors with a 'tag'
subcategory (e.g. https://danbooru.donmai.us/posts?tags=bonocho),
and all 'gfycat' user extractors.
