image/ubuntu: speed up bulding image for provisioning
image/ubuntu: speed up bulding image for provisioning

Bootstrap a system on a journal-less ext4 filesystem, and re-enable
journal afterwards (just before resizing the image).

blueprint support-ubuntu-trusty

Change-Id: I10d1490ee3cb83ad983742c66bdfa1622a603295

dancn/fuel-main-dev,AnselZhangGit/fuel-main,Fiware/ops.Fuel-main-dev,ddepaoli3/fuel-main-dev,SmartInfrastructures/fuel-main-dev,Fiware/ops.Fuel-main-dev,stackforge/fuel-main,SergK/fuel-main,zhaochao/fuel-main,dancn/fuel-main-dev,Fiware/ops.Fuel-main-dev,teselkin/fuel-main,SmartInfrastructures/fuel-main-dev,SergK/fuel-main,dancn/fuel-main-dev,AnselZhangGit/fuel-main,eayunstack/fuel-main,zhaochao/fuel-main,ddepaoli3/fuel-main-dev,SmartInfrastructures/fuel-main-dev,zhaochao/fuel-main,dancn/fuel-main-dev,zhaochao/fuel-main,zhaochao/fuel-main,teselkin/fuel-main,huntxu/fuel-main,teselkin/fuel-main,eayunstack/fuel-main,SergK/fuel-main,stackforge/fuel-main,huntxu/fuel-main,Fiware/ops.Fuel-main-dev,AnselZhangGit/fuel-main,teselkin/fuel-main,huntxu/fuel-main,stackforge/fuel-main,eayunstack/fuel-main,SmartInfrastructures/fuel-main-dev,ddepaoli3/fuel-main-dev,ddepaoli3/fuel-main-dev,AnselZhangGit/fuel-main