Add feature to remove line items from open order cycle

- Add JS controller to send delete requests.
- Add resource controller to destroy items.
- Add authorisation check to abilities.
- Update fees after removing line item.

app/assets/javascripts/darkswarm/controllers/edit_order_controller.js.coffee

@@ -0,0 +1,10 @@
+Darkswarm.controller "EditOrderCtrl", ($scope, $resource, Cart) ->
+
+  $scope.deleteLineItem = (id) ->
+    params = {id: id}
+    success = (response) ->
+      $(".line-item-" + id).remove()
+    fail = (error) ->
+      console.log error
+
+    $resource("/line_items/:id").delete(params, success, fail)

app/assets/javascripts/darkswarm/services/cart.js.coffee

@@ -102,7 +102,6 @@ Darkswarm.factory 'Cart', (CurrentOrder, Variants, $timeout, $http, $modal, $roo
       for line_item in items
         line_item.variant.line_item = line_item
         Variants.extend line_item.variant
-        line_item.variant.extended_name = @extendedVariantName(line_item.variant)
       items
 
     total_item_count: =>