Merge remote-tracking branch 'origin/6.2.0-pubcontent' into 7.0.0-pubcontent

Conflicts:
	src/Umbraco.Core/ObjectResolution/Resolution.cs

src/Umbraco.Core/ObjectResolution/Resolution.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Threading;
 using Umbraco.Core.Logging;
 
@@ -128,6 +129,14 @@ namespace Umbraco.Core.ObjectResolution
         {
             LogHelper.Debug(typeof(Resolution), "Resetting resolution");
 
+            /*
+            var trace = new System.Diagnostics.StackTrace();
+            var testing = trace.GetFrames().Any(frame =>
+                frame.GetMethod().DeclaringType.FullName.StartsWith("Umbraco.Tests"));
+            if (testing == false)
+                throw new InvalidOperationException("Only unit tests can reset configuration.");
+            */
+
             using (new WriteLock(ConfigurationLock))
             {
                 _isFrozen = false;