always move client side read cursor forward when sending message;
always move client side read cursor forward when sending message;

immediately clears unread marker.

nanaya/osu-web,LiquidPL/osu-web,nanaya/osu-web,notbakaneko/osu-web,omkelderman/osu-web,notbakaneko/osu-web,nanaya/osu-web,notbakaneko/osu-web,ppy/osu-web,notbakaneko/osu-web,omkelderman/osu-web,ppy/osu-web,LiquidPL/osu-web,ppy/osu-web,ppy/osu-web,notbakaneko/osu-web,LiquidPL/osu-web,ppy/osu-web,nanaya/osu-web,LiquidPL/osu-web,LiquidPL/osu-web,nanaya/osu-web,omkelderman/osu-web,omkelderman/osu-web