Click sounds on keypress

Although it might be annoying to others (and we might want it off by default) it would be good to be able to enable a click sound when entering a character. This helps users to notice that input worked while looking at the keyboard (not the input area).

@tobias.bernard this is not visual design but I think you might be interested (maybe we should talk about this in the design calls since ring tones, alarms sounds, etc are another area we want well inegrated)