Now determines top-left visible card

Also a bunch of code cleanup for transitions
Focal zoom implementation is far from perfect, but its a big improvement
Removed a log statement
Touch of refactoring, got rid of scrollTop animation, added upscaling back in
Removed transitions -- looks way better -- gah, so much work for naught
Transitioning is never turned on by zooming
Added transitioning back in, for jumping into the card view
Merge branch 'cards-grid'