Added IE8,9 support with iFrame fallback + Added Web Api endpoints

Hi,

I changed quite a bit in your original plugin.
1) Fallback with iframe for older IE browsers
2) Added the option to preload a file. (in my case this was useful for member profile pictures)
3) Added functionality that loads the cropper instead of the uploader when an existing file with 'tocrop'-class is found. that is: when it has been uploaded but not cropped by accident.
4) Added initial zoom option.
5) changed some things with how it all works. Querystrings instead of FormData on the Crop ajax call. etc.

I hope it will be of use to someone. 

Martin