CHANGES BEHAVIOUR: before we launch, check if we can connect to the controlsocket we are about to obliterate. If it works, abort. Fixes #841 and changes standing behaviour. There might be circumstances where PowerDNS now refuses to start, where it previously would. However, starting and making our previous instance mute wasn't good.
Merge branch 'rel/auth-3.3' of github.com:PowerDNS/pdns into rel/auth-3.3