ToggleOnTop icon partially made from:
  http://findicons.com/icon/28530/needleleftyellow?id=277856

Minimize icon partially made from:
  http://findicons.com/icon/217940/minimize?id=428987
  http://www.userinterfaceicons.com/

Restore icon partially made from:
  http://findicons.com/icon/440674/view_restore?id=440895
  http://www.webdesignerdepot.com/