Fixed outdated notes in SchemaEditor docs.

docs/ref/schema-editor.txt

@@ -32,12 +32,10 @@ support foreign key constraints.
 
 If you are writing or maintaining a third-party database backend for Django,
 you will need to provide a ``SchemaEditor`` implementation in order to work with
-1.7's migration functionality - however, as long as your database is relatively
-standard in its use of SQL and relational design, you should be able to
-subclass one of the built-in Django ``SchemaEditor`` classes and tweak the
-syntax a little. Also note that there are a few new database features that
-migrations will look for: ``can_rollback_ddl``
-and ``supports_combined_alters`` are the most important.
+Django's migration functionality - however, as long as your database is
+relatively standard in its use of SQL and relational design, you should be able
+to subclass one of the built-in Django ``SchemaEditor`` classes and tweak the
+syntax a little.
 
 Methods
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