resized

Called by a snip to notify the administrator that the specified snip has changed its display size (without being polled by get-extent). The snips generally needs to be updated after a resize, but the snip decides whether the update should occur immediately.

• (send a-wx:snip-admin resized snip refresh?) -> void
      snip : wx:snip% object
      refresh? : boolean

  If refresh? is not #f, then the snip is requesting to be updated immediately. Otherwise, needs-updatemust eventually be called as well.