Squashed commit of the following:

commit 77f12b02cf4e81f13e10db3cfac90e9de0b53928
Author: Mukund Sivaraman <muks@isc.org>
Date:   Mon Jul 13 05:28:13 2015 +0530

    Some tweaks

commit 9c521020b03c2fe7293ec4c970225fff479efd40
Author: Tony Finch <dot@dotat.at>
Date:   Thu Jul 9 15:36:15 2015 +0100

    rndc addzone error reporting improvements

    Clearer error messages from rndc addzone and modzone when the view is not
    known or when allow-new-zones is off.

    Also, remove a spurious newline from the delzone response.