Single Upload uses fine-tuned icons based on:

FileSquare/Filetypeicons
---------------------------------
author:     FileSquare (http://www.filesq.com)
website:    http://www.filetypeicons.com
location:   /Resources/public/single-upload/img
license:    Creative Commons Attribution-ShareAlike 3.0 Hong Kong License 
            (http://creativecommons.org/licenses/by-sa/3.0/hk/)