Split message about unpacking and loading images
Split message about unpacking and loading images

User could think that master node installation hanged, as lrzip provided
total time and nothing happened next. After lrzip executes there is
additional message warning that image loading may take some time.

PipeViewer was thought of as possible mean to show progress bar to the
user, but because of the way `docker load` command works (it loads the
data first and then processes it) it wasn't a viable option.

To assure good user experience docker load should provide it's own
progress bar or any other indicator, but this change would need to be
made in docker itself.

Change-Id: I57a63a15adfef45a5e68861c91ff09dc281a15e4
Closes-Bug: #1439193

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