U4-4931 - lock contention & potential application lockdown

Conflicts:
	src/Umbraco.Core/Cache/ObjectCacheRuntimeCacheProvider.cs
	src/umbraco.cms/Actions/Action.cs
U4-4931 - fixing & refactoring

Conflicts:
	src/Umbraco.Core/Cache/DictionaryCacheProviderBase.cs
	src/Umbraco.Core/Cache/HttpRuntimeCacheProvider.cs
	src/Umbraco.Core/Cache/ObjectCacheRuntimeCacheProvider.cs
U4-4931 - fixing & refactoring
U4-4931 - fixing & refactoring

Conflicts:
	src/Umbraco.Core/Cache/ObjectCacheRuntimeCacheProvider.cs
U4-4931 - fixing & refactoring

Conflicts:
	src/Umbraco.Core/Cache/DictionaryCacheProviderBase.cs
	src/Umbraco.Core/Cache/DictionaryCacheWrapper.cs
	src/Umbraco.Core/Cache/DictionaryItemWrapper.cs
	src/Umbraco.Core/Cache/HttpRequestCacheProvider.cs
	src/Umbraco.Core/Cache/ObjectCacheRuntimeCacheProvider.cs
U4-4931 - do not cache exceptions

Conflicts:
	src/Umbraco.Core/Cache/DictionaryCacheProviderBase.cs
	src/Umbraco.Core/Cache/HttpRequestCacheProvider.cs
U4-4931 - fixing & refactoring

Conflicts:
	src/Umbraco.Core/Cache/DictionaryCacheProviderBase.cs
	src/Umbraco.Core/Cache/HttpRequestCacheProvider.cs
	src/Umbraco.Core/CacheHelper.cs
	src/Umbraco.Core/Umbraco.Core.csproj
	src/Umbraco.Tests/Cache/HttpRequestCacheProviderTests.cs
U4-4931 - fixing & refactoring

Conflicts:
	src/Umbraco.Core/Cache/HttpRequestCacheProvider.cs
U4-4931 - also for ObjectCacheRuntime provider

Conflicts:
	src/Umbraco.Core/Cache/ObjectCacheRuntimeCacheProvider.cs
Merge branch '7.1.5' into 7.1-4931
added a couple of tests for member names
Added NodeCount property to ITag/Tag and an optional flag to tag retrieval methods on TagsService, in order to retrieve the count for the tag as well as it's text
Fixes some of U4-2633 Bundle all cache refresher transmissions into a single call per request for much better performance. See last note on issue.
U4-4837 - bugfix Umbraco.Core.EnumerableExtensions.InGroupsOf
Merge branch '7.1.5' into 7.1-4931
Ensures that the batched distributed calls doesn't cache refresh the server executing the distributed calls since tht will already be done locally.
Ensures all caching is disabled for editing templates (master pages and views)
Completes: U4-5264 Add Count methods to IContentService, IMediaService, etc...
Merge remote-tracking branch 'origin/6.2.2' into 7.1.5

Conflicts:
	src/Umbraco.Core/Sync/DefaultServerMessenger.cs
	src/Umbraco.Tests/Services/ContentServiceTests.cs
Removed parameter for requesting count for tags and made including the count the default behaviour