css: add skin scrollbar
css: add skin scrollbar

joequant/etherpad-lite,joequant/etherpad-lite,storytouch/etherpad-lite,storytouch/etherpad-lite,storytouch/etherpad-lite,ether/etherpad-lite,ether/etherpad-lite,joequant/etherpad-lite,ether/etherpad-lite,joequant/etherpad-lite