* PIE,RELRO+NOW and other security features enabled
* support for both static/dynamic builds with BUILDMODE
* dynamic library is ABI-versioned, starting at 1
* pkg-config file is installed

module can identify clients based on their source address or used TSIG
key

- zonecut map is now truly a volatile cache to accelerate zone cut
retrieval, RDATA is stored in cache
- cache update is commited after each successfuly resolved query
- SBELT contains a static data as a fallback if the root server cannot
be found in the zone cut map, or the data is missing in the cache