The Delete and Backspace buttons remain enabled in spell check mode, allowing the client to delete selections inside the Editor's content area.

Steps to reproduce:
1. Open http://demos.telerik.com/aspnet-ajax/editor/examples/spellchecker/defaultcs.aspx
2. Click the Spell check icon
3. Select several words from the content and press Backspace/Delete

Result: The selected content is deleted
Expected: The Delete/Backspace button press is ignored