Merge branch '6.0' into 7.0

Author: alex-kulakov

Orm/Xtensive.Orm.Tests.Framework/Orm.config

@@ -119,7 +119,7 @@
     <!-- A hook to have abitity to check and test newer, yet not supported, versions without adding them to the file -->
     <!-- This allows to override it in storage configuration files -->
     <domain name="firebirdnext"
-            connectionUrl="sqlserver://localhost/DO-Tests?MultipleActiveResultSets=True" />
+            connectionUrl="firebird://dotest:dotest@localhost:3053/dotest" />
 
     <domain name="sqlite3"
             connectionUrl="sqlite:///DO-Tests.db3" />