Fixes "Type Error" and missing thumbnail in recent versions of google chrome.

Recent versions of Google Chrome are being built with a flawed version of Chromium which has a bug with the new Image constructor. A bug report is available at: https://code.google.com/p/chromium/issues/detail?id=238071

The fix simply changes the way an Image Object is being created. Tested in my dropzone implementation and its now working fine in google chrome version 27.0.1453.93.