Required syntax changes to support ruby version 1.9

"case" syntax changes and using "node.set[]=" instead of "node[]="
Nagios is not supported on windows clients for the moment

Since nagios is not supported for windows clients at the moment,
it should not apply linux-specific recipes if platform is windows.
Merge pull request #65 from ociuhandu/pull-req-release-pebbles-master-58a2078e8676eb14d4439f36e1ad3e1385f0a21b

https://github.com/crowbar/barclamp-nagios/pull/65

Merged by devtool for VictorLowther