Browser's spell checker is disabled

[PhiLhoSoft]

I see spellcheck=false in the demo.
It is nicer without the squiggly lines, but the spell checking is important in such editor.
I suggest to add a button (and the corresponding API?) to enable / disable the spell checking.
The trick given at http://stackoverflow.com/questions/5601431/spellcheck-false-on-contenteditable-elements can be relevant, I think.