By moving virtualbox logic all within logic that checks if it *is*
within a vbox environment, you can reuse the template safely with other
providers like libvirt/kvm. Also making sure you have the vbox guest
utils.
Merge pull request #923 from KwadroNaut/kvm-vbox

Make Debian template compatible with non-vbox providers
made a mistake on vbox guest utils downloads, fixing last commit
Merge pull request #924 from KwadroNaut/kvm-vbox

Made a mistake on vbox guest utils downloads for debian, improving dc7e52f
Update the url to the Windows 8 evaluation iso
Merge pull request #925 from manics/fix_win8_eval_iso_url

Update the url to the Windows 8 evaluation iso (needs testing)