before root hints were hardcoded to the resolver,
now they are present in form of a cut in the resolution
context, and the modules can add/remove/replace them
on the fly

fixes potential cache key oob write

also some cleanup and version bump to Q2

this LRU-like cache tracks lame nameservers, unresolvable
nameservers (to not waste resources in trying to resolve them),
and possibly other features (extension support, …)

This reverts commit 91a2945e.

Conflicts:
	daemon/worker.h

this avoids repetitive allocation/free cycles on load