Feature/reliable connection (#44)

* Initial commit of reliable connection port

* Made ReliableSqlConnection inherit from DbConnection instead of IDbConnection

* Cleanup

* Fixed autocomplete service to use reliable connection

* Fix copyright headers

* Renamed ConnectResponse.Server to ServerInfo

* Removed unused using

* Addressing code review feedback

src/Microsoft.SqlTools.ServiceLayer/Connection/ReliableConnection/SqlErrorNumbers.cs

@@ -0,0 +1,32 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+namespace Microsoft.SqlTools.ServiceLayer.Connection.ReliableConnection
+{
+    /// <summary>
+    /// Constants for SQL Error numbers
+    /// </summary>
+    internal static class SqlErrorNumbers
+    {
+        // Database XYZ already exists. Choose a different database name.
+        internal const int DatabaseAlreadyExistsErrorNumber = 1801;
+
+        // Cannot drop the database 'x', because it does not exist or you do not have permission.
+        internal const int DatabaseAlreadyDroppedErrorNumber = 3701;
+
+        // Database 'x' was created\altered successfully, but some properties could not be displayed.
+        internal const int DatabaseCrudMetadataUpdateErrorNumber = 45166;
+
+        // Violation of PRIMARY KEY constraint 'x'. 
+        // Cannot insert duplicate key in object 'y'. The duplicate key value is (z).
+        internal const int PrimaryKeyViolationErrorNumber = 2627;
+
+        // There is already an object named 'x' in the database.
+        internal const int ObjectAlreadyExistsErrorNumber = 2714;
+
+        // Cannot drop the object 'x', because it does not exist or you do not have permission.
+        internal const int ObjectAlreadyDroppedErrorNumber = 3701;
+    }
+}