this is not going to be backwards compatible change, but it will be the first tagged libknot release sufficient for resolver

notably key id doesn’t have to be recalculated every time, cheaper checks should come first, name equality check is cheaper as well 

amalgamated build concatenates all files into a single .c file to
allow compiler see all symbols and produce possibly smaller code.
for binary distributions this is what you want, as it's faster but
may consume more memory during compilation.
it however cannot do incremental builds.

if the query has RD=0 or is ANY, only cache is probed
for ANY, only A/AAAA/MX is checked and no query is
forwarded to the authoritatives

Original TTL has not been set.