Only load visible img's even when on bottom of page

I have modified the code for my use and I think it may be useful to add it back in.

Currently if you go to a page with an hash (#something) you may land on the bottom of the page but  all images will be loaded since lazy only tests for `top + _getActualHeight() + configuration.threshold) > (element.offset().top + element.height()`
I added a test if element's bottom is > page top, so that is such a case only images will load (also useful when updating a page with ajax ).

I have also added a test so that the element's info should only be copied to the pseudo img if onError or onLoad is used