Adding IContentManager.Clear() method

--HG--
branch : 1.x

src/Orchard/ContentManagement/DefaultContentManager.cs

@@ -528,6 +528,12 @@ namespace Orchard.ContentManagement {
             return _contentDisplay.Value.UpdateEditor(content, updater, groupId);
         }
 
+        public void Clear() {
+            var session = _sessionLocator.Value.For(typeof(ContentItemRecord));
+            session.Clear();
+            _contentManagerSession().Clear();
+        }
+
         public IContentQuery<ContentItem> Query() {
             var query = _context.Resolve<IContentQuery>(TypedParameter.From<IContentManager>(this));
             return query.ForPart<ContentItem>();

src/Orchard/ContentManagement/DefaultContentManagerSession.cs

@@ -21,5 +21,10 @@ namespace Orchard.ContentManagement {
         public bool RecallContentRecordId(int id, out ContentItem item) {
             return _publishedItemsByContentRecordId.TryGetValue(id, out item);
         }
+
+        public void Clear() {
+            _itemByVersionRecordId.Clear();
+            _publishedItemsByContentRecordId.Clear();
+        }
     }
 }

src/Orchard/ContentManagement/IContentManager.cs

@@ -77,6 +77,11 @@ namespace Orchard.ContentManagement {
         /// Flushes all pending content items to the persistance layer
         /// </summary>
         void Flush();
+        
+        /// <summary>
+        /// Clears the current referenced content items
+        /// </summary>
+        void Clear();
 
         /// <summary>
         /// Query for arbitrary content items

src/Orchard/ContentManagement/IContentManagerSession.cs

@@ -3,5 +3,7 @@
         void Store(ContentItem item);
         bool RecallVersionRecordId(int id, out ContentItem item);
         bool RecallContentRecordId(int id, out ContentItem item);
+
+        void Clear();
     }
 }