This Class map and get roles/projects for accounts

  Examples:

    roles_for :administrator do |role, current_account|
      role.allow_all_actions "/backend/base"
      role.deny_action_of    "/backend/accounts/details"

      role.project_module :administration do |project|
        project.menu :general_settings, "/backend/settings" do |submenu|
          submenu.add :accounts, "/backend/accounts" do |submenu|
            submenu.add :sub_accounts, "/backend/accounts/subaccounts"
          end
        end
      end

      role.project_module :categories do |project|
        current_account.categories.each do |cat|
          project.menu cat.name, "/backend/categories/#{cat.id}.js"
        end
      end
    end

  If a user logged with role administrator or that have a project_module administrator can:

  - Access in all actions of "/backend/base" controller
  - Denied access to ONLY action <tt>"/backend/accounts/details"</tt>
  - Access to a project module called Administration
  - Access to all actions of the controller "/backend/settings"
  - Access to all actions of the controller "/backend/categories"
  - Access to all actions EXCEPT <tt>details</tt> of controller "/backend/accounts"