Create system2iso_last

This snippet creates an ISO from the sys2iso folder. It invokes another script called 'system2iso_distro-defaults' that takes care of the isolinux/syslinux boot screen and the manual clean up.
TODO: 
- inherit environment variables from a wrapper 
- the whole framework is written for casper, we should make it work for casper, live-boot, dracut. This can be achieved by user input or by checking if casper or live-boot or dracut is installed.