Adding two missing properties to ContentTypeBase.

Creating mappers for the few types that supports "db queries" through the repository U4-978

src/Umbraco.Core/ExpressionHelper.cs

@@ -82,6 +82,43 @@ namespace Umbraco.Core
 					});
 		}
 
+        public static MemberInfo FindProperty(LambdaExpression lambdaExpression)
+        {
+            Expression expressionToCheck = lambdaExpression;
+
+            bool done = false;
+
+            while (!done)
+            {
+                switch (expressionToCheck.NodeType)
+                {
+                    case ExpressionType.Convert:
+                        expressionToCheck = ((UnaryExpression)expressionToCheck).Operand;
+                        break;
+                    case ExpressionType.Lambda:
+                        expressionToCheck = ((LambdaExpression)expressionToCheck).Body;
+                        break;
+                    case ExpressionType.MemberAccess:
+                        var memberExpression = ((MemberExpression)expressionToCheck);
+
+                        if (memberExpression.Expression.NodeType != ExpressionType.Parameter &&
+                            memberExpression.Expression.NodeType != ExpressionType.Convert)
+                        {
+                            throw new ArgumentException(string.Format("Expression '{0}' must resolve to top-level member and not any child object's properties. Use a custom resolver on the child type or the AfterMap option instead.", lambdaExpression), "lambdaExpression");
+                        }
+
+                        MemberInfo member = memberExpression.Member;
+
+                        return member;
+                    default:
+                        done = true;
+                        break;
+                }
+            }
+
+            throw new Exception("Configuration for members is only supported for top-level individual members on a type.");
+        }
+
 		public static IDictionary<string, object> GetMethodParams<T1, T2>(Expression<Func<T1, T2>> fromExpression)
 		{
 			if (fromExpression == null) return null;