reference data
remove hints from top level menu to improve visibility
support v6prefix tests
allow null or ipv6 prefix
fix json parsing bug
Merge pull request #740 from cloudedge/pull-req-master-7b2595345449549a947599bce19b7b2359708d68

https://github.com/crowbar/barclamp-crowbar/pull/740

Merged by devtool for VictorLowther