Added ability for set "dead zone" which give us ability to moving Im…

[rizhenkov]

Added ability for set "dead zone" which give us ability to moving Image faster to the edges (see screenshots).

Before this option, for moving to corner, cursor need to be here: http://i.imgur.com/h8WKVLj.png But now, with "dead zone" we can set padding-like area: http://i.imgur.com/1Tq6sw2.png Using: $('#ex1').zoom({ deadZone: 40 }); // set "dead zone" padding to 40px