Functionnality : Strip conserving content

[Nuranto]

Current behavior :

Shortcode::strip($string) will remove a shortcode like this : [link href="/toto"]Toto[/link] => `` (empty)

Proposal :

It would be great to add a parameter into strip method in order to keep or not the content, so we can strip like this : [link href="/toto"]Toto[/link] => Toto