livecd-init: uuids clone: gen-uuids is renamed to livecd-uuids

- $GR/gen-uuids.git is moved to $GR/livecd-uuids.git
- The "gen-uuids" branch in gen-uuids.git is renamed to "livecd-uuids"

b09d84fa-25db-11e4-85da-c80aa9e67bbd