Allow automatic full-height resolution

I have been testing this with Chrome, and I noticed that inferring the "full-content" height using the expression:

    newHeight = $(element).data().boxHeight + "px";

leaves my content truncated since the approximated height turns out to be insufficient (in some test cases). Changing this to "auto" fixed the problem for all test cases variants I tried to come up with.

Am testing this with Chrome 25.0.1364.172 and Firefox 21.0