During agent data update, only update the pages when timestamp is recent

From what I understand, Glimpse server update pages on the wiki with all the Data received from the application, even if these data have been received some days ago.We could say that we update object pages only if the timestamp of the update is not older than 1 hour. This is better for the 'update agent data' page which now have a realistic number of how many hosts are sending data, and also it should be better for the wiki (less pages to check and to update)