Add kiwibuild wrapper script to change the image name without touching config.xml

- Create empty dir /var/log/journal
- Remove /var/log/journal/.gitignore in images.sh
- Convert /etc/sysconfig/network/ifcfg-eth0 to overlay file
- sed ifcfg-eth0 with the correct IP in images.sh
- Convert the nameservers to bash array in images.sh