Merge remote-tracking branch 'origin/v8/dev' into vx/feature/unicore

# Conflicts:
#	src/Umbraco.Abstractions/EnumerableExtensions.cs
#	src/Umbraco.Abstractions/Models/Entities/EntityBase.cs
#	src/Umbraco.Core/Models/Member.cs

src/Umbraco.Core/Models/Entities/EntityExtensions.cs

@@ -0,0 +1,46 @@
+using System;
+
+namespace Umbraco.Core.Models.Entities
+{
+    internal static class EntityExtensions
+    {
+        /// <summary>
+        /// Updates the entity when it is being saved.
+        /// </summary>
+        internal static void UpdatingEntity(this IEntity entity)
+        {
+            var now = DateTime.Now;
+
+            // just in case
+            if (entity.CreateDate == default)
+            {
+                entity.CreateDate = now;
+            }
+
+            // set the update date if not already set
+            if (entity.UpdateDate == default || (entity is ICanBeDirty canBeDirty && canBeDirty.IsPropertyDirty("UpdateDate") == false))
+            {
+                entity.UpdateDate = now;
+            }
+        }
+
+        /// <summary>
+        /// Updates the entity when it is being saved for the first time.
+        /// </summary>
+        internal static void AddingEntity(this IEntity entity)
+        {
+            var now = DateTime.Now;
+            var canBeDirty = entity as ICanBeDirty;
+
+            // set the create and update dates, if not already set
+            if (entity.CreateDate == default || canBeDirty?.IsPropertyDirty("CreateDate") == false)
+            {
+                entity.CreateDate = now;
+            }
+            if (entity.UpdateDate == default || canBeDirty?.IsPropertyDirty("UpdateDate") == false)
+            {
+                entity.UpdateDate = now;
+            }
+        }
+    }
+}