Fix WP save method for linked resources

frontend/app/components/api/api-v3/hal/hal-resource.service.ts

@@ -96,7 +96,9 @@ function halResource(halTransform, HalLink, $q) {
       element._links = {};
 
       linked.forEach(linkName => {
-        element._links[linkName] = this[linkName];
+        if (this[linkName] && !angular.isFunction(this[linkName])) {
+          element._links[linkName] = element[linkName].$links.self.$link;
+        }
 
         delete element[linkName];
       });

frontend/app/components/api/api-v3/hal/work-package-resource.service.ts

@@ -49,13 +49,16 @@ function wpResource(HalResource: typeof op.HalResource) {
     }
 
     save() {
-      var data = this.$plain();
+      const plain = this.$plain();
 
       //TODO: Remove non-writable properties automatically
-      delete data.createdAt;
-      delete data.updatedAt;
+      delete plain.createdAt;
+      delete plain.updatedAt;
 
-      return this.$source.patch(data);
+      return this.$links.updateImmediately(plain).then(workPackage => {
+        angular.extend(this, workPackage);
+        return this;
+      });
     }
   }