Closing file stream before moving file to destination

From [Images not showing](http://forum.broadleafcommerce.org/viewtopic.php?f=15&t=2441). Using IOUtils to close streams before moving files. Fixes BroadleafCommerce/DemoSite#81
Merge pull request #769 from xshyamx/patch-1

Fixes #769 - Closing file stream before moving file to destination to properly deal with uploading images on Windows