Fix resource URLs: resource:\narwhal

[cadorn]

I started to report on FireConsole + Firebug but I didn't get toob far...I get a ton of error messages like

tabCache.loadFromCache EXCEPTION on url 'resource:\narwhal\engines\default\lib\json.js' Component returned failure code: 0x80040111(NS_ERROR_NOT_AVAILABLE) [nsIIOService.newChannel]

because I guess the backslashes are not legal in urls.