Update pdns auth init script so it works on wheezy

insserv would complain:
insserv: There is a loop at service pdns if started
insserv: There is a loop between service pdns and mountall if started
insserv: There is a loop between service pdns and mountall-bootclean if started
insserv: Starting rsync depends on pdns and therefore on system facility `$all' which can not be true!
stretch supermasters.ip for IPv6, thanks Dennis Krul
also stretch supermasters.ip for goracle
make sure systemd starts pdnsd after relevant databases have been started, thanks Morten Stevens
Merge pull request #847 from zeha/f/insserv

Update pdns auth init script so it works on wheezy
bump boost requirement, thanks Wouter de Jong
initialise server-id after all parsing is done, instead of half way through. Fixes situations where server-id was emptied explicitly. Reported by Wouter de Jong
Merge branch 'master' of https://github.com/PowerDNS/pdns into clang-master