GTextEditor: Improvements to cursor rendering.

The view now scrolls along with you as you move the cursor around.

Applications/TextEditor/main.cpp

@@ -104,6 +104,7 @@ int main(int argc, char** argv)
     window->set_rect(20, 200, 640, 400);
     window->set_main_widget(widget);
     window->set_should_exit_app_on_close(true);
+    text_editor->set_focus(true);
     window->show();
 
     return app.exec();