Implement ReplaceSelection output handling.

External 'sort' now works as it should.

src/plugins/texteditor/texteditorplugin.h

@@ -77,6 +77,7 @@ private slots:
     void invokeQuickFix();
     void updateSearchResultsFont(const TextEditor::FontSettings &);
     void updateVariable(const QString &variable);
+    void updateCurrentSelection(const QString &text);
 
 private:
     static TextEditorPlugin *m_instance;