Add enabled & editable properties

Hi
I've stumbled upon this and it was exactly what I was looking for. I made a few changes that you might like to check. It just adds two attributes: enabled and editable.

enabled: allows to disable the toggle and adds a 'disabled' class to reflect its status.
editable: it only disables the toggle.

Sorry if I'm missing some 'github etiquette', I'm new to this.

Thanks for your work

mgmaestri