ANN: dns.0.7.0, sodium.0.1.0 and dnscurve.0.1.0

[Anil Madhavapeddy <anil@xxxxxxxxxx>]

Three new libraries published to OPAM.  Thanks to David Sheets for driving much 
of this.

DNS 0.7.0 sees a big refresh in the interface, and the moving out of some of 
the more complex logic (such as DNSSEC) to a separate library.  This lets us 
introduce DNSCurve, which is being used as part of Signposts [1] to provide 
confidential and secure DNS resolution to client resolvers.

The Sodium library is a binding to DJB's NaCl library, and is also a good 
usecase for Ctypes.

Changelogs and homepages:
https://github.com/mirage/ocaml-dns/blob/master/CHANGES
https://github.com/dsheets/ocaml-dnscurve
https://github.com/dsheets/ocaml-sodium

Note that Sodium in particular hasn't undergone extensive peer review yet, so 
don't consider it NSA-resistent just yet.

[1] http://anil.recoil.org/papers/2013-foci-signposts.pdf

Coming soon: a localhost proxy for DNSCurve.

-anil