added ability to set attrib from API with tests.  Fixed issue w/ method_missing.
expose atribs on node screen
Merge pull request #668 from cloudedge/pull-req-master-1e1d51f3a00255be609e66e7e29427b97c63f986

https://github.com/crowbar/barclamp-crowbar/pull/668

Merged by devtool for VictorLowther