performance: move image scripts higher (even in the head)

It would dramatically improve perceived performance for images (in non supporting browsers), if you would move picturefill (and the lazyloader) either as first script in body or even in the head (in that case async attribute would also be awesome, but not a must).

Otherwise a lot of other scripts need to be downloaded before picturefill can even start to do it’s magic.

https://wordpress.org/plugins/wp-retina-2x/