AjaxFileUpload

This is a fork version of http://www.phpletter.com/Our-Projects/AjaxFileUpload/

Improvement and Fix

1. Add arguments support
   You can now use data to send addictional arguments, Example:

    $.ajaxFileUpload(
    {
        url: '/',
        secureuri: false,
        data: {                    
            'name': 'carlcarl',
        },
        ...
        ...
    }
   

2. Fix mimetype problem
   If you add mimetype in your json response, it will add addictional tags '<pre></pre>' to your ajax response, which will cause error in original code.
   So I fix this.