Squashed commit of the following:

commit 318214175cd5ce0917ac4895822872860e2129a8
Author: bert hubert <bert.hubert@netherlabs.nl>
Date:   Sun Dec 21 15:44:09 2014 +0100

    add public-suffix-list filtering for ringbuffer output, like top-pub-servfail-queries and top-pub-queries

commit 402cc7c2f8f1fc1cf0002375d3bbffb9d429c509
Author: bert hubert <bert.hubert@netherlabs.nl>
Date:   Sat Dec 20 15:13:03 2014 +0100

    oops, add that too, missed this in previous commit

commit 462e9498e9a6b78b7a774e97137b4ff3611a71e1
Author: bert hubert <bert.hubert@netherlabs.nl>
Date:   Sat Dec 20 15:11:07 2014 +0100

    make our query rings qtype aware, plus implement prototype public suffix grouping (still very stupid)

commit d63d313ca61f8d9991e41a34429497613b22ee0f
Author: bert hubert <bert.hubert@netherlabs.nl>
Date:   Fri Dec 19 10:40:52 2014 +0100

    implement further statistics, top-servfail-remotes, top-largeanswer-remotes, top-servfail-queries

commit a4c21b423b583640f2fcb1a65577727a2ef81727
Author: bert hubert <bert.hubert@netherlabs.nl>
Date:   Fri Dec 19 09:03:29 2014 +0100

    improve ringbuffers in recursor, add query ringbuffer + infra to get top queries
and the .hh file, sorry
actually make pubsuffix.cc in dist
document dnsgram, document where to find the powerdns tools (thanks AJ & friends)
ok, you can't call 'make' from dist-recursor..
this fixes an accidental commit, but leaves some parts in place. Specifically, our 'beenthere' checks
were accidentally refusing to re-ask anything if *either* ipv4 or ipv6 had asked them already. This is now
sorta fixed.
park ed25519 directory in ext