Cloudtest: Support for Ubuntu 13.10

In order to allow an Ubuntu 13.10 cloud testing platforms I needed to do the following adaptions:
* Allow for 'non-root' login user name after image bootup (the Ubuntu 13.10 cloud image has a restricted shell when logging in as 'root' stating one should log in as 'ubuntu')
* Setup script without root permissions (until now the setup script ran as 'root', now it might run as 'ubuntu' and therefore needs some permission related fixes)

The Ubuntu contextualization script for 12.04 can be reused for 13.10.