Hidden: Source Beta 4 Client Update

This is a client update for Hidden Source - apply it over the top of an existing Beta 3 install.
In "The Hidden", players choose the role of either a near invisible killer, Subject 617, or one member of an Intercept squad who have to capture him, I.R.I.S. In the simple but challenging gameplay of an 'one against all'? mode, Subject 617 creeps/sn