Input mode Switching

Run with `scripts=on` and `strict-focus=off`

1. If page is loade, vimb should be in input mode.
2. Set `strict-focus=on` and reload page. Vimb should keep in normal mode
3. Independent from the `strict-focus` should vimb switch to input mode if the button is clicked

Also the following element using `contenteditable="true"` should switch vimb into input mode on click.

Clicking this element using contenteditable="true" should switch vimb into input mode too.