Fixes booting hp dl380G8 machines.
Fixes /etc/network/interfaces.

Fixes non-failing error whereby the us mirror was used, instead of our local.

Removes lines that are not compatible with ubuntu's implementation of
kickstart.

Calls curl in the target chroot , as 14.04 does not have curl on the
installation media.

Introduces configurable credentials as I could not find them in the config.yml.
Introduces a new config option for the location of grub.exe, used to replace
sanboot.

Also introduces config options for the user that connects to Collins and sets
the (re-)installed machine to 'Provisioned'.
Merge pull request #1 from mverwijs/blendle-fixes

Blendle fixes