this allows us to specify an arbitrary chroot command, i.e. for sudo

builder/virtualbox: Fix scancode comment concerning key release

According to the scancode reference, the release key code is generated by
adding `0x80` to the key press code, not `0x81`.

builder/virtualbox: fix scancodes for F1-F12 and delete

Support for the backspace, delete and F1-F12 keys was added in commit 6028a3c.
However, that commit seems to have copied character codes from the vmware
builder into the VirtualBox builder. Character codes are appropriate for VMware
which communicates through a VNC. However, VirtualBox communicates through
simulating raw keyboard input and therefore needs scancodes which are key
press/key release sequences.

This patch converts backspace, delete and F1-F10 to scancodes. F11 and F12 are
not listed in the [scancode reference][scancodes] so they have been omitted.

[scancodes]: http://www.win.tue.nl/~aeb/linux/kbd/scancodes-1.html

fix iso_url: use old-releases.ubuntu.com/...

provisioner/puppet-masterless: remove duplicate manifest upload message

repeatably

provisioner/puppet-masterless: facter vars may collide with puppet command

website: accidently a word

specifically, "builders"