TextEditors: Move some auto-indentation code to document

From the editor widget. Also name them autoIndent/autoReindent to
distinguish from the manual indent functions.

Change-Id: I4e1b9d503f53870b669fee66467e5e567eacefec
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/designer/qtcreatorintegration.cpp

@@ -309,7 +309,7 @@ static void addDeclaration(const Snapshot &snapshot,
             tc.beginEditBlock();
             tc.insertText(loc.prefix() + declaration + loc.suffix());
             tc.setPosition(pos, QTextCursor::KeepAnchor);
-            editor->indentInsertedText(tc);
+            editor->baseTextDocument()->autoIndent(tc);
             tc.endEditBlock();
         }
     }