Add/remove tags in dic_tags for 2.1

[weaverryan]

The dic_tags document is basically complete for 2.0, but there are some changes necessary for 2.1:

• kernel.cache_clearer
• translation.dumper
• translation.extractor
• and remove security.listener.factory

[stof]

kernel.event_subscriber has been added in 2.1 too

[weaverryan]

Yep, thanks for catching that. I've just merged from 2.0, and actually it turns out the kernel.event_subscriber was one that was already covered. So, we're already good for kernel.event!

[wouterj]

this is also discussed in #519. @weaverryan could you please determine in which issue you want to continue and close the other?

[weaverryan]

I've summarized all of this in #2347, so closing this one in favor of it!