Install a VirtualBox host system.

    More Infos:
     * overview:     https://wiki.ubuntuusers.de/VirtualBox/
     * installation: https://wiki.ubuntuusers.de/VirtualBox/Installation/

def virtualbox_host():
    '''Install a VirtualBox host system.

    More Infos:
     * overview:     https://wiki.ubuntuusers.de/VirtualBox/
     * installation: https://wiki.ubuntuusers.de/VirtualBox/Installation/
    '''
    if query_yes_no(question='Uninstall virtualbox-dkms?', default='yes'):
        run('sudo apt-get remove virtualbox-dkms')
    install_packages([
        'virtualbox',
        'virtualbox-qt',
        'virtualbox-dkms',
        'virtualbox-guest-dkms',
        'virtualbox-guest-additions-iso',
    ])
    users = [env.user]
    for username in users:
        run(flo('sudo  adduser {username} vboxusers'))