Merge branch 'master' into dev

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/Query.cs

@@ -99,6 +99,12 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
         /// </summary>
         public event Batch.BatchAsyncEventHandler BatchCompleted;
 
+        /// <summary>
+        /// Delegate type for callback when a query connection fails
+        /// </summary>
+        /// <param name="q">The query that completed</param>
+        public delegate Task QueryAsyncErrorEventHandler(string message);
+
         /// <summary>
         /// Callback for when the query has completed successfully
         /// </summary>