Fix IE7/8/9 Bug

initializeDimensions is called two times, once in the init method and again in the handeImageLoad method. On InternetExplorer, sometimes, the first call is executed before the image is load, so sometimes the plugin fail in IE.
Changed unbind to off, More precise targeting

* Changed all 'unbind' to 'off'
* More precise targeting of events using the original event type plus
namespace name
* It should also be possible to run the off(base.namespace) on top level
element to target all in the namespace but did not seem to work
Merge git://github.com/Sirk/jWindowCrop