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.
404 when a Tool does not exist by the given slug
Merge pull request #711 from opscode/missing-tool-404s

404 when a Tool does not exist by the given slug
Merge pull request #707 from opscode/tool-collaborators-ui

Implement Collaborators for Tools
Implement tool search

Tools search can be toggled from anywhere in the application and tool
search is toggled by default when in any tool related sections of the
application.
Focus the search input after changing search type.
More explicitly set the default search.