system and per-user configuration files

[glenwiley]

It would be good to support an optional system wide and per user configuration file that affects the run-time performance of the getdns library. If the files do not exist then the library runs the way it is currently designed to.

The system wide configuration would be in /etc/getdns.conf and the per user file would be ~/.getdns.conf

Some of the elements addressed in the configuration files include:

• special behavior for particular zones, forwarding, etc.
• whether to accept dhcp provided resolvers or override with manually specified resolvers
• default settings in the context such as stub vs. recursive mode for the library
• cache behavior - whether to share with the system or per user, another issue addresses this in more detail

[wtoorop]

Both stubby and getdns_query have this option. So allthough not implemented in the library, it is trivial to implement this from an application using the library.