Initial commit of the Vagrant module

The first commit of the Vagrant module which will provide out of the box VM's (based on VirtualBox) which will be provisioned with XWiki.

This will be useful in the following scenarios:

1) One-click downloads of VM and have XWiki out of the box pre-installed and pre-configured
2) Allow performing automated tests (especially ui-tests) on different environments
3) Easy testing of our Debian packages which Thomas created some time ago. They seem pretty used by the community.

The baseBox used with this first commit is Ubuntu Quantal 12.10 (Quantal Quetzal) 64-bit machine. Due to its quite large filesize, we might use a smaller sized base box.
The provisioning is still in early stages, adding a xwiki user to the system and modifying the hostname and MOTD file.

For more information, check the comments in the pom.xml file