Use correct font size for list of nodes for roles

(cherry picked from commit 840f9258d5c46ae372a6c06518d6e16fa98a5b34)
Merge pull request #955 from vuntz/fix-font-size-stoney

Use correct font size for list of nodes for roles
Unify finder methods and refactor them up to Chef Object
Fix references to query methods
All chef look ups are centralized, so we can bechmark them easily
Use the new finders in BarclampController#transition
Fix merge changes