Adding "Flush" method to content manager

This is needed when you need to make queries that rely on state changed inside the session UOW.

--HG--
extra : convert_revision : svn%3A5ff7c347-ad56-4c35-b696-ccb81de16e03/trunk%4045743

src/Orchard/ContentManagement/DefaultContentManager.cs

@@ -362,6 +362,10 @@ namespace Orchard.ContentManagement {
             return query.ForPart<ContentItem>();
         }
 
+        public void Flush() {
+            _contentItemRepository.Flush();
+        }
+
         private ContentTypeRecord AcquireContentTypeRecord(string contentType) {
             var contentTypeRecord = _contentTypeRepository.Get(x => x.Name == contentType);
             if (contentTypeRecord == null) {

src/Orchard/ContentManagement/IContentManager.cs

@@ -18,6 +18,7 @@ namespace Orchard.ContentManagement {
         void Unpublish(ContentItem contentItem);
         void Remove(ContentItem contentItem);
 
+        void Flush();
         IContentQuery<ContentItem> Query();
 
         ContentItemMetadata GetItemMetadata(IContent contentItem);