to support urls for CSS cursor properties, nsIWidget::SetCursor(imgIContainer*)
needs to be implemented for the window.
bug 38447 implemented this for windows and gtk2.
This bug has been buried in the graveyard and has not been updated in over 5 years. It is probably safe to assume that it will never be fixed, so resolving as WONTFIX.
[Mass-change filter: graveyard-wontfix-2014-09-24]