I'm using iTerm 2.1.4 and Tmux on OS X Yosemite. I'd like to be able to scroll my iTerm windows up and down but I'm not sure what controls scrolling. Does tmux control scrolling when I use it with iTerm or does iTerm still control scrolling? I've tried using the various keys that are supposed to scroll iTerm but all I get are "~~~~~" characters on the command line. How do I scroll with this setup?