Fixed the new constraints instance accessor

(cherry picked from commit 565e3f4ac93dddec518e88b0469237685dd10470)
Integrated software raid
Refactored crowbar service for better readability
Simplified claiming commands that include save method
Removed regex match and replaced it with a string function
Synced disk claiming with deployer, added crowbar wall initial value
Fixed single disk raid naming
Renamed save_it to transition_save_node
Updated unique device path order

For details you can see the reference here:
https://github.com/crowbar/barclamp-deployer/blob/release/stoney/master/chef/cookbooks/barclamp/libraries/barclamp_library.rb#L320
Merge pull request #923 from tboerger/feature/software-raid

Integrated software raid
Merge pull request #977 from vuntz/release/stoney/master

Fixed the new constraints instance accessor