DNSCurve patch for djbdns-1.05

I finally had some extra free time earlier today to polish my djbdns
DNSCurve patch to the point of feeling comfortable publishing it.  You
can download the patch from:

    http://shinobi.dempsky.org/~matthew/patches/djbdns-dnscurve-20090529.patch

There are build instructions and some brief notes at the top of the
patch.  Be sure to read the notes before installing.

If you would like to test out how the patch works with a
DNSCurve-aware name server, you can try resolving some names within
x.dempsky.org.  E.g., after running "dnstxt hello.x.dempsky.org", you
should see

    tx 0 16 hello.x.dempsky.org. x.dempsky.org. + 46551f42

in your dnscache logs.  The "+" indicates that this query was sent
using DNSCurve.

Still on my TODO for this patch is to support storing DNSCurve public
keys in the roots/servers/ files.  I'm thinking something like
allowing

    70.85.31.66:uz5p4utwsxu5p3r9xrw0ygddw2hxh7bkhd0vdwtbt92lf058ny1p79

in roots/servers/x.dempsky.org (i.e., using the same encoding that
public keys in name server names use).

Feedback and comments appreciated.

Thanks.