Log Message:
Update to version 1.6.17.

For the complete change log of the ldns container, see ../../net/ldns.
Changes relevant to drill:

 * README now shows preferred way to configure for examples and drill.
 * Bind to source address for resolvers. drill binds to source with -I.
   Thanks Bryan Duff.
 * bugfix #497: Properly test for EOF when reading key files with drill.
 * bugfix #521: drill trace continue on empty non-terminals with NSEC3
 * New RR types HIP, NINFO, RKEY, CDS, EUI48, EUI64, URI, CAA and TA.