Prevent additional suffixes on filenames...

... which may throw off MIMEtype detection. Seems to be dependent on
OS, so Ubuntu didn't have the issue which CentOS did. Fun times!

Jira: https://jira.duraspace.org/browse/ISLANDORA-901
Ontime Ticket 2260

![screen shot 2013-08-22 at 10 04 19 am](https://f.cloud.github.com/assets/607975/1009161/62dfd000-0b34-11e3-9eb1-07f0d686eb22.png)