2.0.0

The element is now fully inline, its CSS use a lot the em unit, to keep the button's size synced with its font-size value.
The class slidebutton-focus will be set when the button has the focus.
The class slidebutton-checked will be set when the button is checked.

1.1.0

Important fix about the checked attribute.
And the README is written.

1.0.0

First try :)