Bump preinstalled Ubuntu image to 12.04.2
Merge pull request #78 from VictorLowther/pull-req-release-pebbles-master-a0c8ce902ba2ff2b08a2b4fcf2938992f2e17f34

https://github.com/crowbar/barclamp-glance/pull/78

Merged by devtool for VictorLowther