Merge branch '6.0' into 7.0

# Conflicts:
#	Orm/Xtensive.Orm.MySql/NuGetContent/ReadMe.md
#	Orm/Xtensive.Orm.Oracle/NuGetContent/ReadMe.md

Author: alex-kulakov

Orm/Xtensive.Orm.MySql/NuGetContent/ReadMe.md

@@ -16,7 +16,7 @@ or, alternatively, use connection string like
 
 ```csharp
     var domainConfiguration = new DomainConfiguration("mysql",
-	  "Server=localhost;Port=3306;Database=tests;Uid=someuser;Pwd=Sometest;");
+	  "Server=localhost;Port=3306;Database=tests;Uid=someuser;Pwd=somepassword;");
 ```
 
 After that, if connection settings are valid, build Domain and use it as usual.

Orm/Xtensive.Orm.Oracle/NuGetContent/ReadMe.md

@@ -15,7 +15,7 @@ Create a domain configuration configuration with connection url similar to this
 or, alternatively, use connection string like
 
 ```csharp
-    var domainConfiguration = new DomainConfiguration("mysql",
+    var domainConfiguration = new DomainConfiguration("oracle",
 	  "DATA SOURCE="(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=xe)))";USER ID=someuser;PASSWORD=somepassword");
 ```