Sometimes markup gets in the way

It seems that, at the moment, there's a reliance that the scrolling container be a first degree parent to the elements that are being snapped to. I can't see how this is always (or even often) the case. I am using Bootstrap which unfortunately adds some crud between the body (which scrolls) and my sections so the `container + ' > ' + section` qualification really doesn't work. When you know that your 'section selector' is unique I don't see why there needs to be this qualification, especially if there's no dimensional difference between body and the layers between it and your section (though I haven't looked at exactly how the offset calculations are made).

I have added an option which switches off the direct descendant qualifier to fix this for me.