Update to 4.1.11

Changelog:
1 August 2016: Wouter
        - Tag 4.1.11rc1.
        - Fix nsec3 missing for nsec3 signed parent and child for DS at zonecut.
        - Tag 4.1.11rc2.

8 July 2016: Wouter
        - Note down tracking numbers for issue JVN#63359718 JPCERT#91251865.

5 July 2016: Wouter
        - Fix #790: size-limit-xfr can stop NSD from downloading infinite zone
          transfer data size, from Toshifumi Sakaguchi.

27 June 2016: Wouter
        - Set default for min-refresh-time and min-retry-time to 0.  Behaves
          just like before, but has a configurable option in nsd.conf.
        - Fix #783: Trying to run a root server without having configured it
          silently gives wrong answers.

16 June 2016: Wouter
        - When tcp is more than half full, use short timeout for tcp session.
        - Patch for {max,min}-{refresh,retry}-time from YAMAGUCHI Takanori.
        - man page entries for max-refresh-time patch.

15 June 2016: Wouter
        - Fix build without IPv6, patch from Zdenek Kaspar.

(ryoon)