Change Vagrant base box to a custom box made by elkuku

The base box we are currently using is giving this funny error the last couple of days:
![dropboxs__509](https://f.cloud.github.com/assets/33978/2175227/c385e338-95bb-11e3-8ee4-5f88e6ef8b39.png)

Not sure if Dropbox mentions this anywhere, but "temporarily" lasts at least for the last three days...

So I decided to bake my own one and hope that it does not get too popular ;)

The first steps have been done using this excellent script: https://github.com/dotzero/vagrant-debian-wheezy-64
I then went on installing the latest VBox additions and tried to reduce it in size.

Please test.