On Fri, Sep 13, 2013 at 9:16 AM, Juan Pablo Lorier <jplorier gmail com> wrote:
close
button for the windows without exiting all of the opened windows
Alt+F4 does that
There is also a "Close" item in the gear menu (on 3.8 at least). As was stated above, a persistent close button on maximized windows will be coming in 3.10.