buildlive: Reuse cached initramfs

During build we generate an initramfs with live support and we want to
reuse it here.

Issue: #27
Pick support files from $workdir/support instead of $workdir/images

We used to pick images support files from $workdir/images, but it
conflicts with the directory that holds built images so we choose
to rename it to support.
mauibuild-image-pull-deploy: Create an ext3 file system rather than ext4

dracut only supports it.

Issue: #27