#244: ajax_data.js, add 'contentType', and 'processData'
#244: ajax_data.js, add internal documentation on '@contentType'
#244: ajax_data.js, add internal documentation on '@processData'
#244: ajax_data.js, additional internal documentation on '@contentType'
#244: ajax_data.js, send 'arr_data', instead of 'form_data' array
#244: ajax_data.js, change key 'file' -> 'file_data_' + index, 'form_data.append()'
#244: ajax_data.js, properly assign 'file_data' for 'formData'
#244: ajax_data.js, properly assign 'form_data' to ajax 'data' property
#244: ajax_data.js, remove unnecessary 'arr_data'
#244: ajax_js, change 'console.log(arr_data)' -> 'console.log(form_data)'
Merge pull request #264 from jeff1evesque/js_ajax_data

#244: Send 'file upload' from ajax to PHP