Comment improvements (antispam)

[reppep]

When deleting a spam comment, it should be easy (checkbox) to delete the account(s) too.

It should be easy to see users with 0 comments, so we can purge them (I don't think there's any other reason to register for my blogs, so I'm pretty sure all such users are spammers whose posts I've deleted).

Some posts look like valid content but I suspect they are trying to drive traffic to their sites. I'd like an option to approve a comment, but prevent the Website field from showing up to avoid giving them traffic or pagerank.

[xave]

There are no accounts for comments submiters.