[#9] added cancan permissions for guest users (members of the public)
[#9] Access to unpublished articles handled by cancan rules.
[#9] Spaces instead of tabs for GuidesController
[#9] Fallback to no related articles if Searchify can't be accessed.

* E.g. when in dev and no internet, or when the service goes down
[#9] Alert when viewing unpublished articles.