Required syntax changes to support ruby version 1.9

"case" syntax changes and using "node.set[]=" instead of "node[]="
DNS is handled differently on Windows.

If platform is Windows, do not write the resolv.conf
Merge pull request #52 from ociuhandu/pull-req-release-pebbles-master-58a2078e8676eb14d4439f36e1ad3e1385f0a21b

https://github.com/crowbar/barclamp-dns/pull/52

Merged by devtool for VictorLowther