Merge commit '94d525d88f713b36419f28bfda4d82ee68637d83' into v9/dev

# Conflicts:
#	build/NuSpecs/UmbracoCms.Web.nuspec
#	src/Umbraco.Core/Composing/Current.cs
#	src/Umbraco.Core/Persistence/NPocoDatabaseExtensions-Bulk.cs
#	src/Umbraco.Core/Runtime/CoreRuntime.cs
#	src/Umbraco.Infrastructure/Migrations/Upgrade/UmbracoPlan.cs
#	src/Umbraco.Infrastructure/Persistence/NPocoDatabaseExtensions.cs
#	src/Umbraco.Infrastructure/Persistence/UmbracoDatabase.cs
#	src/Umbraco.Persistence.SqlCe/SqlCeSyntaxProvider.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/BTree.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/ContentCacheDataModel.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/ContentCacheDataSerializationResult.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/ContentCacheDataSerializerEntityType.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/ContentData.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/ContentNestedData.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/CultureVariation.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/IContentCacheDataSerializer.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/IContentCacheDataSerializerFactory.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/IDictionaryOfPropertyDataSerializer.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/JsonContentNestedDataSerializer.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/JsonContentNestedDataSerializerFactory.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/LazyCompressedString.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/MsgPackContentNestedDataSerializer.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/MsgPackContentNestedDataSerializerFactory.cs
#	src/Umbraco.PublishedCache.NuCache/DataSource/PropertyData.cs
#	src/Umbraco.PublishedCache.NuCache/NuCacheSerializerComponent.cs
#	src/Umbraco.PublishedCache.NuCache/NuCacheSerializerComposer.cs
#	src/Umbraco.Tests.Integration/Umbraco.Infrastructure/Services/ContentTypeServiceVariantsTests.cs
#	src/Umbraco.Tests/App.config
#	src/Umbraco.Tests/PublishedContent/NuCacheChildrenTests.cs
#	src/Umbraco.Tests/PublishedContent/NuCacheTests.cs
#	src/Umbraco.Tests/Scoping/ScopedNuCacheTests.cs
#	src/Umbraco.Web.UI.NetCore/umbraco/config/lang/da.xml
#	src/Umbraco.Web.UI/web.Template.Debug.config
#	src/Umbraco.Web.UI/web.Template.config
#	src/Umbraco.Web/Composing/ModuleInjector.cs
#	src/Umbraco.Web/Editors/NuCacheStatusController.cs
#	src/Umbraco.Web/PublishedCache/NuCache/DataSource/ContentNestedData.cs
#	src/Umbraco.Web/PublishedCache/NuCache/DataSource/DatabaseDataSource.cs
#	src/Umbraco.Web/PublishedCache/NuCache/NuCacheComposer.cs
#	src/Umbraco.Web/PublishedCache/NuCache/PublishedSnapshotService.cs
#	src/Umbraco.Web/Runtime/WebRuntime.cs

src/Umbraco.Infrastructure/Serialization/AutoInterningStringConverter.cs

@@ -0,0 +1,37 @@
+using System;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace Umbraco.Cms.Infrastructure.Serialization
+{
+
+    /// <summary>
+    /// When applied to a string or string collection field will ensure the deserialized strings are interned
+    /// </summary>
+    /// <remarks>
+    /// Borrowed from https://stackoverflow.com/a/34906004/694494
+    /// On the same page an interesting approach of using a local intern pool https://stackoverflow.com/a/39605620/694494 which re-uses .NET System.Xml.NameTable
+    /// </remarks>
+    public class AutoInterningStringConverter : JsonConverter
+    {
+        public override bool CanConvert(Type objectType)
+        {
+            // CanConvert is not called when a converter is applied directly to a property.
+            throw new NotImplementedException($"{nameof(AutoInterningStringConverter)} should not be used globally");
+        }
+
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            if (reader.TokenType == JsonToken.Null)
+                return null;
+            // Check is in case the value is a non-string literal such as an integer.
+            var s = reader.TokenType == JsonToken.String
+                ? string.Intern((string)reader.Value)
+                : string.Intern((string)JToken.Load(reader));
+            return s;
+        }
+
+        public override bool CanWrite => false;
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();
+    }
+}

src/Umbraco.Infrastructure/Serialization/AutoInterningStringKeyCaseInsensitiveDictionaryConverter.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+
+namespace Umbraco.Cms.Infrastructure.Serialization
+{
+    /// <summary>
+    /// When applied to a dictionary with a string key, will ensure the deserialized string keys are interned 
+    /// </summary>
+    /// <typeparam name="TValue"></typeparam>
+    /// <remarks>
+    /// borrowed from https://stackoverflow.com/a/36116462/694494
+    /// </remarks>
+    public class AutoInterningStringKeyCaseInsensitiveDictionaryConverter<TValue> : CaseInsensitiveDictionaryConverter<TValue>
+    {
+        public AutoInterningStringKeyCaseInsensitiveDictionaryConverter()
+        {
+        }
+        public AutoInterningStringKeyCaseInsensitiveDictionaryConverter(StringComparer comparer) : base(comparer)
+        {
+        }
+
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            if (reader.TokenType == JsonToken.StartObject)
+            {
+                var dictionary = new Dictionary<string, TValue>();
+                while (reader.Read())
+                {
+                    switch (reader.TokenType)
+                    {
+                        case JsonToken.PropertyName:
+                            var key = string.Intern(reader.Value.ToString());
+
+                            if (!reader.Read())
+                                throw new Exception("Unexpected end when reading object.");
+
+                            var v = serializer.Deserialize<TValue>(reader);
+                            dictionary[key] = v;
+                            break;
+                        case JsonToken.Comment:
+                            break;
+                        case JsonToken.EndObject:
+                            return dictionary;
+                    }
+                }
+            }
+            return null;
+        }
+
+    }
+}

src/Umbraco.Infrastructure/Serialization/CaseInsensitiveDictionaryConverter.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using Newtonsoft.Json.Converters;
@@ -14,12 +14,24 @@ namespace Umbraco.Cms.Infrastructure.Serialization
     /// </example>
     public class CaseInsensitiveDictionaryConverter<T> : CustomCreationConverter<IDictionary>
     {
+        private readonly StringComparer _comparer;
+
+        public CaseInsensitiveDictionaryConverter()
+            : this(StringComparer.OrdinalIgnoreCase)
+        {
+        }
+
+        public CaseInsensitiveDictionaryConverter(StringComparer comparer)
+        {
+            _comparer = comparer ?? throw new ArgumentNullException(nameof(comparer));
+        }
+
         public override bool CanWrite => false;
 
         public override bool CanRead => true;
 
         public override bool CanConvert(Type objectType) => typeof(IDictionary<string,T>).IsAssignableFrom(objectType);
 
-        public override IDictionary Create(Type objectType) => new Dictionary<string, T>(StringComparer.OrdinalIgnoreCase);
+        public override IDictionary Create(Type objectType) => new Dictionary<string, T>(_comparer);
     }
 }