Rescue invalid IRC log dates

Potentially an invalid IRC log date could be passed as a param to the
IrcLogsController. Rescue this and return a 404.
Enable deep linking on Foundation tabs

So you can link directly to a Foundation tab, enable deep linking data
attribute.
Support tool slugs as route params

A slug will now be generated from the tool name, which can be changed by
the user. The tool slug is used as the tools route param.
Merge pull request #704 from opscode/make-tabs-linkable

Enable deep linking on Foundation tabs
Merge pull request #703 from opscode/rescue-invalid-irc-dates

Rescue invalid IRC log dates
Merge pull request #693 from opscode/slugify-tools

Support tool slugs as route params
Change CookbookCollaborator to Collaborator

To support the same cookbook collaboration features for tools this
changes CookbookCollaborator to Collaborator with a polymorphic
association that could be either Cookbook, Tool or some other feature
resource.
Ensure resourceable_id uniqueness is scoped to user_id and resourceable_id.
Ensure to only find cookbook collaborators when deleting a cookbook.
Only allow Collaborators to be created for tools and cookbooks.
Limit number of users returned from collaborators index, include chef_account.
Ensure collaborator unique index is on user_id, resourceable_type and resourceable_id.