[archlinux] VirtualBox post-installation steps

This is printed after installation of virtualbox-sun package.
So, if you prefer virtualbox-ose (Open Source Edition) since Sun is now a part of Oracle, check these points :

»> NOTE:
»>  - Run “sudo /etc/rc.d/vboxdrv setup”, every time your kernel is upgraded,
»>    to compile virtualbox driver modules for a new kernel version.
»>  - Add your users to the vboxusers group:
»>      gpasswd -a USERNAME vboxusers
»>  - Customize your “/etc/conf.d/vboxdrv”; usually, defaults are OK.
»>  - Add “vboxdrv” to DAEMONS array in your “/etc/rc.conf”, if needed.
»>  - If USB does not work for you out-of-the-box, add the following line
»>    to your “/etc/fstab”:
none /proc/bus/usb usbfs auto,busgid=108,busmode=0775,devgid=108,devmode=0664 0 0
Dépendances optionnelles pour virtualbox-sun
    dkms: for building and loading VirtualBox modules
    qt: for Oracle VirtualBox QT4 GUI on X-Window System
    sdl: for Oracle VBoxSDL and VirtualBox GUI on console
    vfuse: for mounting VBox (VDI/VMDK/VHD) disk images