WIP - much simpler height-resize fix for mozilla/browserid#3476.

    Works on IE8.
    Works on browsers that actually support window.outerHeight: IE9, Chrome, FF.
    Works on iOS 6 because window.resizeTo() is ignored by MobileSafari.
    Android testing not yet done.
    TODO borderline insane laziness to copy code in 2 places and add a note to
    keep the two copies in sync. Should probably move into one single file.