Merge pull request #17 from theodi/master

pulling from master
Added 'can :read, Dataset' to CanCan
Adding feature to access datasets as atom feeds, through the route 'datasets/:id/to_atom' and xml_feed.rb
Changed route from 'to_atom' to 'atom.xml'
addressing issues raised on PR
including the route helpers in the xml_feed.rb file
Merge pull request #542 from The-Skas/feature/atom

Feature/atom