New VirtualBox version

[lazzurs]

A new VirtualBox version is out. This is not just a patch release but a new minor version.

http://www.oracle.com/us/corporate/press/2033376
https://www.virtualbox.org/wiki/Changelog

Having a quick look I did not see anything that would not just work in the build with the new version other than the directory structure being changed. Do you want a pull request for this?

Thanks.