Changed the featured image cropping logic

Now uses src rather than background.

Converted magazine layout to use wells like traditional layout.
Enabled animation on infinite scroll

This is a user triggered event so animation is allowed.  This visually
shows the user where new articles get placed.
Added padding below the featured image
Removed twp_featured_image

Used the standard the_post_thumbmail methods instead now that src is being
used for the images.