Support arrays of actions in can statements

[CyborgMaster]

I find myself wanting to define a lot of permissions on both create and update (if a user can create a record with a given field, they most likely are also allowed to update that field. This isn't too bad when it's just a few fields, but I have a complex model that requires the following statements:

            can :create, :name, :photo_file_name,
              :photo_content_type, :photo_file_size, :photo_updated_at, :photo,
              :photo_original_w, :photo_original_h, :photo_box_w, :photo_crop_x,
              :photo_crop_y, :photo_crop_w, :photo_crop_h, :photo_aspect
            can :update, :name, :photo_file_name,
              :photo_content_type, :photo_file_size, :photo_updated_at, :photo,
              :photo_original_w, :photo_original_h, :photo_box_w, :photo_crop_x,
              :photo_crop_y, :photo_crop_w, :photo_crop_h, :photo_aspect

Not only is this very verbose, it's a problem for maintenance as the field list changes.

I've modified the can statement to optionally take an array of actions allowing the previous examples to be completed in one command.

            can [:create, :update], :name, :photo_file_name,
              :photo_content_type, :photo_file_size, :photo_updated_at, :photo,
              :photo_original_w, :photo_original_h, :photo_box_w, :photo_crop_x,
              :photo_crop_y, :photo_crop_w, :photo_crop_h, :photo_aspect

[CyborgMaster]

I just updated the pull request to modify the cannot function in the same manner as can. They both now support an array of actions as the first parameter.