Allow disabling/selecting the default blocklist

[jonasraoni]

Maybe the user should be able to disable and/or select a default blocklist (I saw some lists here, perhaps they could be downloaded on demand or added as a submodule).

[ctgraham]

The current approach uses the top10000 from that repo as the default, and then allows the user to add any additional blacklists, always using them all. What this doesn't allow for is for the user to say, "I only want to block the 1000 worst passwords, not the 10000 worst passwords", but that sounds like a bad use-case.

[jonasraoni]

Here I just would like to allow the user to easily opt-in for, let's say the top1000000 =]

But it's just a suggestion, if you're going to close this issue, I think it's good to at least display more information about the default blocklist in the settings form (the amount of records/from where it comes).