Removed unavailable boxes

Ubuntu Oneiric 64, cause GitHub does not allow download of big blobs.

Not Found boxes (HTTP/1.1 404 Not Found):

* Archlinux 2011.08.19 - 64: this box redirects to http://sourceforge.net;
* Debian Lenny 32 puppet;
* Debian Lenny 32;
* Debian Wheezy amd64 minimal (base install  ... just an install');
* Fedora 18 x86_64 Minimal (with Puppet, VirtualBox 4.2.6 and rpmfusion);
* OpenBSD 5.0 (i386);
* OpenSUSE 12.1 64 puppet (until 2012-12-17): the message "The application/octet-stream file vagrant-opensuse-121-64.box (524 379 648 bytes) uploaded onto the Inria exchange server by Remy.Garrigue@inria.fr on 17-07-2012 at 17:34 for five months has reached its time limit, and has been removed)" is displayed instead the box content.