Adds tag support for any IContentBase and to the MediaRepository, adds test to ensure tags relations are removed.

src/Umbraco.Core/Persistence/RepositoryFactory.cs

@@ -85,7 +85,8 @@ namespace Umbraco.Core.Persistence
             return new MediaRepository(
                 uow,
                 _disableAllCache ? (IRepositoryCacheProvider)NullCacheProvider.Current : RuntimeCacheProvider.Current,
-                CreateMediaTypeRepository(uow)) { EnsureUniqueNaming = _settings.Content.EnsureUniqueNaming };
+                CreateMediaTypeRepository(uow),
+                CreateTagsRepository(uow)) { EnsureUniqueNaming = _settings.Content.EnsureUniqueNaming };
         }
 
         public virtual IMediaTypeRepository CreateMediaTypeRepository(IDatabaseUnitOfWork uow)