`.selected` is now able to return `br` nodes consistently across browsers.

Before this commit, `.selected` would have never returned `br` elements in Chromium while returning `br` elements in other browsers.

This made it impossible to use `.selected` in order to get a caret position that is at a `br` element.

This compensates for it and now `.selected` can be used, for example, in unit tests, such as `strictEqual(wymeditor.selected(), someBrNode, 'Yup, this is the same node, exactly.');`.