Add crowbar-status and crowbar-failed in schema

Otherwise, barclamp_mgmt_lib.rb will edit the schema and add them, which
will make the files differ from the ones in the package.

Part of https://bugzilla.novell.com/show_bug.cgi?id=776583
Set proposal_schema_version to 2 in crowbar.yml

This is needed when we have crowbar-status/crowbar-failed in the schema.
Merge pull request #53 from vuntz/add-missing-attributes

https://github.com/crowbar/barclamp-ipmi/pull/53

Merged by devtool for cloudsleuth
There si no IPMI support in Windows in this implementation

IPMI management tools are not available in windows so all linux-specific
parts have to be executed only on supported platforms.
Fixed the test of node platform together with the testing of the ipmi
tools availability.