This short document is intended to shed some light on
the philosophy behind ldns.

Closely match the api/interface of Perl's Net::DNS; make it easy to 
toss around RR sets, DNS packets, Resolvers, etc. etc.

As said in 'CodingStyle':
* Everything by reference, all data structures an optional _clone() function

This means that unless something is cloned in a program, it is hard to free
it. The only exception to this in ldns itself is in the resolver structure. 
There the .domain ans .nameservers are cloned when they are put in the
structure. This allows a program to free a resolver structure.
