Code review comment for lp://staging/~adeuring/vmbuilder/jenkins_kvm-optionally-use-juju-test-packages

> I'm okay with changing launch_kvm, however, changes must be generic and not
> specific. launch_kvm is used to buid a variety of images.

I've changed launch_kvm.sh and standalone.sh to accept accept another parameter, --cloud-init-file. The value(s) of this parameter is(are) passed to write-mime-multipart.