Adjust Tool & Cookbook authorizers to be more consistent

Adjust Tool & Cookbook authorizers to be consistent for permissions
surrounding collaborators.
Abstract commonalities between Tool & Cookbook

Abstract commonalities surrounding Tool & Cookbook into the more generic
domain of resources and move more collaborator oriented helper methods
into the CollaboratorHelper module.
Merge pull request #707 from opscode/tool-collaborators-ui

Implement Collaborators for Tools