jsHints

new progress arguments, Firefox 3.6 support, and increased speed

fixed bug where event caching marked loading imgs with new src as alr…

…eady loaded

empty callback error bugfix

backwards compatibility, and increased speed of repeated calls

use `if` over ternary for conditionals

use jQuery Deffered object

Always reset src, to resolve IE9 bug

event.target instead of this in imgLoaded

filter for images as well