Autocomplete bug fixes (#43)

Fix-up the autocomplete support to better handle binding timeouts.
Also provide a default keyword suggestion list.

test/Microsoft.SqlTools.ServiceLayer.Test/Utility/TestObjects.cs

@@ -67,14 +67,6 @@ namespace Microsoft.SqlTools.Test.Utility
             return new LanguageService();
         }
 
-        /// <summary>
-        /// Creates a test autocomplete service instance
-        /// </summary>
-        public static AutoCompleteService GetAutoCompleteService()
-        {
-            return AutoCompleteService.Instance;
-        }
-
         /// <summary>
         /// Creates a test sql connection factory instance
         /// </summary>