created wiki model, controller, and associated users to wiki
added a collaborators function to Wiki, updated Wiki#Update
cleaned up views, updated Wiki controller update action to handle adding collaborators a little better
added markdown support
Added validation to Wiki, fixed word-wrap on Wiki Show view
additional changes to views, Users now have a role and premium flag, authorizations added to wiki controller
renamed application.css
added mac stuff to gitignore
vim stuff for gitignore just in case