Merge remote-tracking branch 'origin/v8/dev' into netcore/dev

# Conflicts:
#	src/Umbraco.Infrastructure/Runtime/SqlMainDomLock.cs
#	src/Umbraco.PublishedCache.NuCache/PublishedSnapshotService.cs
#	src/Umbraco.Web.UI.Client/src/views/users/user.controller.js
#	src/Umbraco.Web/Models/Trees/MenuItemList.cs
#	src/Umbraco.Web/Runtime/WebInitialComposer.cs
#	src/Umbraco.Web/Trees/RelationTypeTreeController.cs
#	src/Umbraco.Web/UmbracoApplication.cs

src/Umbraco.Infrastructure/Models/ContentEditing/RelationTypeDisplay.cs

@@ -13,6 +13,9 @@ namespace Umbraco.Web.Models.ContentEditing
             Notifications = new List<BackOfficeNotification>();
         }
 
+        [DataMember(Name = "isSystemRelationType")]
+        public bool IsSystemRelationType { get; set; }
+
         /// <summary>
         /// Gets or sets a boolean indicating whether the RelationType is Bidirectional (true) or Parent to Child (false)
         /// </summary>

src/Umbraco.Infrastructure/Models/Mapping/RelationMapDefinition.cs

@@ -39,6 +39,8 @@ namespace Umbraco.Web.Models.Mapping
             target.Udi = Udi.Create(Constants.UdiEntityType.RelationType, source.Key);
             target.Path = "-1," + source.Id;
 
+            target.IsSystemRelationType = source.IsSystemRelationType();
+
             // Set the "friendly" and entity names for the parent and child object types
             if (source.ParentObjectType.HasValue)
             {