updates NodeDto and PropertyTypeDto to auto-gen GUIDs by default

src/Umbraco.Core/Models/Rdbms/NodeDto.cs

@@ -9,6 +9,12 @@ namespace Umbraco.Core.Models.Rdbms
     [ExplicitColumns]
     internal class NodeDto
     {
+        public NodeDto()
+        {
+            //By default, always generate a new guid
+            UniqueId = Guid.NewGuid();
+        }
+
         public const int NodeIdSeed = 1050;
 
         [Column("id")]

src/Umbraco.Core/Models/Rdbms/PropertyTypeDto.cs

@@ -9,6 +9,12 @@ namespace Umbraco.Core.Models.Rdbms
     [ExplicitColumns]
     internal class PropertyTypeDto
     {
+        public PropertyTypeDto()
+        {
+            //by default always create a new guid
+            UniqueId = Guid.NewGuid();
+        }
+
         [Column("id")]
         [PrimaryKeyColumn(IdentitySeed = 50)]
         public int Id { get; set; }