fix dual-stack superslave when multiple namservers share a ip
Revert "Check that the domain isn't already served by the new master"

This reverts commit 3b797caab6583a6a7452a0eaf45fd7a670b4242c.
don't addSuckRequest after supermaster zone creation to avoid simultaneous AXFR for the new zone
Merge pull request #1184 from mind04/supermaster

More supermaster stuff