Matteo Corti <matteo@corti.li>

Thanks:

* Many thanks to Elan Ruusamäe <glen@delfi.ee> for the improved parallel support and several fixes
* Many thanks to Victor V Kudlak <info@kentos.ru> for the parallel support
* Many thanks to Jan Kantert <jan.kantert@researchgate.net> for the whitelisting support
* Many thanks to Nick Nicholas <opoudjis@gmail.com> for IPv6 support
* Many thanks to Michael Orlitzky <michael@orlitzky.com> for the test.sh usage patch
* Many thanks to Celevra https://github.com/celevra for the Debian/Ubuntu documentation update
* Many thanks to Claudio Kuenzler https://github.com/Napsty for the append patch and several improvements
* Many thanks to Oliver Rahner https://github.com/oliverrahner for the --url patch
* Many thanks to Nikolas Obser https://github.com/nikolasobser for the symlink patch
* Many thanks to waja (https://github.com/waja) for the dnsbl.inps.de patch
